The Knight is an odd melee class. It tries to encapsulate the theme, but ultimately it just fails pretty hard. If you try to make the Knight as WotC imagines him, he is very MAD (STR, DEX, CON, CHA). The early levels are pretty strong, but it is overall weak for a physical melee class. A real problem is the Knight's Challenge feature: the DCs for these abilities are low to begin with, and to raise them you have to invest in more levels in Knight, and Charisma. The abilities sound good, but they are further limited by the fact that they can't affect unintelligent creatures, and you have few uses of them per day. They are a poor man's maneuvers from Tome of Battle. The buffing challenges do not even give good buffs. Another problem with the Knight is the Knight's Code. This causes three small problems, like forgoing flank bonuses and not being able to damage a helpless opponent. It's sometimes worse than a Goody Goody Paladin, but sometimes better. It's still Lawful Stupid. For this reason, the Knight is usually used as a dip for its signature ability, Bulwark of Defense. This is an amazing ability for a lockdown build. Otherwise, a Knight can be taken for flavor in a charger or mounted build. Regardless, pure Knight is pretty horrible. Her capstone ability is cool, but compared to the save-or-die CC flying around at that level, staying alive won't be your problem, but being effective will be. A knight shines as a lockdown tripper or a mounted charger.
Hit Die: d12 – The largest possible HD on a character that can really use it. You can skip points in CON for some INT to get Combat Expertise/Combat Reflexes.
Base Attack Bonus: Full – Important to have regardless of build.
Saves: Bad Fort, Bad Ref, Good Will – It's unfortunate and odd that Fort is a bad save. CON can remedy this, but with your big HD it might be wiser to pump other stats. Ref saves will be fine, as many Knights utilize high DEX in AoO/control/tripper builds. At least your good save is Will, so not the worst of the double bad save classes.
Skill Points: 2 + INT – You don't really need any more than 2 points, and you will most likely get 1 more from investing in 13 INT for Combat Expertise/Improved Trip. You will want points in only a few things, and maybe some skill tricks if you're a charger. Besides that, your skill list is short and bad, so you don't have anything to put skills in anyway.
So depending on how you build the Knight, these can change significantly. Charisma and Wisdom are pretty universally bad choices, though.
Strength – An important score, but possibly not as good as DEX if you are a finesse, chain-chain tripper. Regardless, you want this as high as possible for all build styles of Knight. This helps you succeed at hitting and tripping, and for a damage-based build is the one stat that can make the difference. This is gold for chargers and ordinary Knights. You want a minimum 12 here.
Dexterity – Depending on what sort of Knight you are creating, you will prioritize either STR or DEX. DEX gives more AoO for use with Combat Reflexes, which is a necessary component of AoO-based disabler/staller/tripper Knights. DEX is wotherwise less useful because your bonus will be limited by the armor you are wearing. Keep this high on Combat Reflexes/Weapon Finesse builds, but STR still governs damage and chance to hit. This is an all-or-nothing stat.
Constitution – CON is a bit overrated on the Knight, but always keep a good CON on all classes. That's just how it goes. If you want to maximize your ability to take a beating, go ahead. This is less important though, or rather, there are more important things to focus on if you want to exploit the Knight. You will probably help your party more with better damage and attack than CON. I recommend a minimum of 10 and a maximum of 14.
Intelligence – As this stat is only used for Combat Expertise to Improved Trip, you need a minimum of 13 points of INT. If and only if you are taking those feats. If not, then dump this stat to 10. If you're really tight on points, you can make it without Improved Trip.
Wisdom – Governs your Will saves and perception skills, but that's it. You have good Will, and you'll never be good at spotting and listening. You don't really want to dump this stat, but you certainly should treat it as your dump stat. Don't need it over 8 or 10, ever.
Charisma – The traditional dump stat for Melee builds. Unfortunately, the Knight's Challenge scales off of CHA. Fortunately, putting points in CHA is a trap. The Knight's Challenge abilities are outright bad. Even with good CHA, they still don't have a good chance to hit. Lots of enemies will be immune to them, and the buffs are not even worth your action almost always. If you for some reason have to be the party face, it's nice to have synergy, but otherwise it's just going to make you too MAD. Perhaps in some campaigns as a pure Knight, you can put a 12, 14, or 16. For most campaigns, this is your 2nd dump stat.
Knights are looking for medium-large races that give them STR or DEX. CON is nice, but not as nice as the other two. You don't want to be small, because it hurts your damage and ability to use trips, etc. As you can use Feats to really trick out the Knight's battlefield control through multiclassing and whatnot, you can't beat the bonus Feat™.
HumanSRD – As a Knight is primarily Melee, stat bonuses to his STR, DEX, and CON are helpful. However, many Knight builds are feat-intensive, and thus the Human's bonus feat cannot be ignored. Also gives you extra skill points to spend on … something. Still a solid choice due to the effect Feats can have on a Knight. Top tier pick, as usual.
Lesser ZenythriMMII+PGtF – The ultimate cheesy use of the Lesser Planetouched rules in Player's Guide to Faerun. Bonuses to STR, DEX, and WIS, with only a penalty to CHA. If that's not broken enough, you get True Strike as a SLA (hahah), Sonic, Fire and Electric Resistance 5, and to top it off Racial skills: Balance and Survival. Balance is a good class skill to put 5 points in, so I'm a fan. The best possible race for a Combat Reflexes build. Honestly, all of the Lesser Planetouched races are busted, I'm just highlighting the most fair/best ones because your DM WILL shoot down the ones created from races in Dragon Magazine.
Lesser ChaondMMII+PGtF – Gold because gold is the color of cheese. +4 DEX, +2 CON, -2CHA. SLAs like Zenythri, but more focused on pumping DEX up. IMHO, not as good as Zenythri, but still broken.
Mineral WarriorDotU – Hailed as the most broken +1 LA template for Melee classes and tanks. Having said that, you may not want it if you prefer to have levels. It has natural armor, burrow speed, huge DR, darkvision, and gets +2 STR, +4CON, with -2 to all mental ability scores. I personally do not think LA is optimal for a real game, but that doesn't change how good this template is.
Lesser Air GenasiPGtF+FRCS – This is a cheesy race using a variant rule. However, it is highly effective and pretty fair stats-wise, with a unique spread. It has bonuses to DEX and INT, with penalties to WIS and CHA. It has some special abilities and SLAs, including Levitate.
Lesser Earth GenasiPGtF+FRCS – Like the Air Genasi, but with CON bonus instead of DEX. Better for chargers. You also get Pass Without Trace, which is nice, but you probably won't be misleading people playing a Knight. Favored Class Fighter, if it matters.
Lesser TieflingSRD+PGtF – Good for those tripper-AoO builds, the classic Tiefling with a side of cheese to dodge the +1 LA. This covers your INT and gives you some DEX to help. Useless SLAs included. Also, it's a cool race. No bias, I swear.
DragonbornRotD – This is a template. Gives +2 CON and -2 DEX on top of the base race's ability mods, the Dragonblood subtype, and the size and movement speed from your base creature. Can be an okay choice, but I don't like this for Knights because you really want STR or DEX bonus. This can be a nice addition to another race that has a STR bonus though.
GoliathRoS – Costs +1 LA. You get +4 STR, +2 CON, -2 DEX as well as powerful build, which improves damage and general combat effectiveness. Better than half-giant, cuts the psionic crap you won't use and gets some more STR. Still not a great choice. It's best with LA-buyoff available.
Half-GiantSRD – Costs +1 LA. The Goliath for people limited to SRD, or doing some weird psionic build where you go War Mind (not a bad choice) and get the Reach power. Loses 2 STR, is strictly worse unless you do that.
ChangelingECS – This race has no stat mods, but is a shapechanger subtype. It can change forms to any medium size race, and can speak a lot of languages potentially (useful for Knight's Challenge lol?). The real reason you take this is to get into Warshaper and/or qualify for Inhuman Reach. This is not very Knightly, though.
Strongheart HalflingFRCS – If you're set on being small for some reason, this is the best choice, as it is a small Human. The only case to make for this race mechanically is if you need to be a charger in a game with a lot of small spaces where you can't charge with a large mount. Mounts must be Large size if you're medium, so if you're small you can have a medium mount and still make mounted charges. If your DM isn't a strict about sizing and fitting creatures, then this is less good.
Snow ElfFB – Now here's an elf you can use. +DEX/-CHA! Perfect for AoO builds. Random weaknesses to fire, a common type, but it is quite usable.
OrcSRD – Orc Knights can be rad. Big strength bonus, penalties to mental stats that you didn't really need or can recover from. More for a charger than a control build. Don't get a lot of other special things.
DarfellanSW – A good race if you expect to encounter water. They have STR bonus with DEX penalty, so you want this race for a standard Knight or charger. They have some minor abilities which let them swim well, and a bite attack. Solid.
KillorenRotW – This is an interesting race with no stat bonuses by default. They are fey, so that confers them some immunities. Every morning this race can choose to manifest an aspect which gives them special abilities, such as a smite attack, bonus to INIT, and other skills.
NecropolitanLM – This would be better if your HD was't already d12. Still comes with a lot of resistances because you become undead, but with no CON score, invalidates CON bonuses/penalties. I would never pick this, but maybe it fits for you.
Hill DwarfSRD – Their stat adjustments are not really what you're looking for, but it's better than other options. Good for countering a DM who likes to trip and bull rush.
Fire ElfUA – This is actually an Elf you could consider in a tripper build, so I'm highlighting it. It has +DEX/-CON like normal, but also +INT/-CHA, so you can put 1 point in INT and then have the 13 you need. It is advantageous and point-efficient for point buy if you want to be an Elf tripper, but you get no great special abilities and the CON penalty is something you want to avoid.
Silverbrow HumanDM – As with the human, but you trade the skill points for the Dragonblood subtype, which can allow you to choose feats for Dragonblooded characters. You don't want any of those feats, though, so this is just a dumb variant. Also, use Feather Fall as a SLA 1/day per 5HD. If you're in a Skyworld campaign.
Half-OrcSRD – You take a -2 hit to INT and CHA, but gain a +2 bonus to STR. Only for charger Knights, and not very good in general.
ElvesSRD+others – Elves don't give you the stats you want, and inflict a CON penalty almost always. For all +DEX/-CON elves, they pretty much suck. Only usable for a finesse tripper.
GnomeSRD – Every gnome variant has a STR penalty, and the bonus to CON is not worth the trade.
WarforgedECS – Sounds cool, right? Not actually efficient, though. The gigantic list of immunities can make it alright.
1 Armor Proficiency: All Armor and All Shields – Check. No tower shields, not that you'll want one.
1 Weapon Proficiency: All Martial – As expected, but no bonuses by default to certain weapons.
1 Fighting Challenge +1 (Ex) – A horrible ability. The bonuses do not scale well, it's hard to hit, doesn't last very long, and if you mess up, you are punished. Not worth using for very long.
1 Knight's Code (Ex) – A really bad part of the Knight that stays with you forever, becuase if you violate it when you don't have Knight's Challenges to use, you end up with a big -2 to saves and attacks for the whole day. It's best to save your challenge uses as a buffer for violating your code, probably. Otherwise, play a pacifist, which is quite viable with a tripper disabler.
2 Mounted Combat (Feat) – A free feat, and it's certainly useful. Even as a tripper, you can trip mounted, and for chargers this is pretty nice.
2 Shield Block +1 (Ex) – You must be using a shield to benefit from this at all, and even then it works like dodge where you can only add the bonus AC vs a single foe. Doesn't scale quickly, and the benefits of a 2-handed weapon don't outweigh this if you have high STR.
3 Bulwark of Defense (Ex) – Although it is technically not the signature ability of the Knight, it might as well be. This causes all space you threaten to become difficult terrain for your foes. This means that they cannot 5-foot step sideways away from you, nor can they step into you with a normal weapon. Because of how reach weapons work, if you have them between you and your threatening squares, they can't get away from you without provoking an AoO. This is why the Knight uses an AoO build so effectively. It's even worse (for the enemy) if you use a spiked chain, which threatens all the space between you and your maximum reach. This also works while mounted – you can threaten more squares with either a reach weapon or a regular weapon because you occupy all the squares your mount occupies. There's tons of combos enabled by this ability, and even if you don't utilize them, this can help your party out a lot with staying safe.
4 Armor Mastery [Medium] (Ex) – Ignore speed reduction incurred by wearing medium armor. Cool, but you'll be mounted in a lot of builds.
4 Test of Mettle (Ex) – Probably the best Knight's Challenge ability. It is an AoE taunt that is hard to hit because the MAD Knight can't pump his DC's, but you target all enemies that can be affected in a 100ft radius so that makes it a little better. Foes affected MUST attempt to attack you and target you, even if their attacks are AoE, magic, whatever. The problem is, once your friends attack an enemy, the effect ends, so plan out what the kill order is beforehand. Not that it lasted more than 5 rounds anyway. On a hilarious note, this ability refunds Challenge uses if you are reduced to 0 HP by an enemy affected.
5 Bonus Feat – This bonus feat is from a list that benefits chargers. You'll be picking from Ride-By Attack, Spirited Charge, Trample, and Weapon Focus (Lance), as the rest are trash.
5 Vigilant Defender (Ex) – This ability is less useful because a lot of levels in Knight is not something too desirable. However, this makes tumbling through your threatened squares even more difficult, and it doesn't take any actions or investment, so it's alright. It doesn't really matter though if you get Thicket of Blades stance from somewhere (and you should).
6 Shield Ally (Ex) – A cool flavorful ability that I tend to like. You can burn an immediate action to absorb half of the physical damage dealt to an adjacent ally. You can opt to keep absorbing half damage for the rest of the round each time more damage is dealt, too. This does not work on spells or multi-target effects. This works on your mount, and is pretty good since you don't have a special mount. There's no limit to its use, too.
7 Fighting Challenge +2 (Ex) – So lame. This is where people exit the Knight class, right before this slap in the face. It's all downhill from here.
8 Call to Battle (Ex) – A hilariously underpowered use of your Knight's challenge. This is a swift action which gives a second save to an ally under a fear effect. As if there were not already enough bonuses to resist fear effects from classes like this.
9 Armor Mastery [Heavy] (Ex) – As the prior version of the ability, but now you can ignore movement penalties from heaviest armor. Since you have to go through 2 dead levels beforehand, the opportunity cost is steep. Also, you will likely be mounted most of the time. Not okay.
10 Bonus Feat – The same list of bonus feats, you get to pick again.
11 Shield Block +2 (Ex) – Improved Dodge, the Class Ability! *Requires shield and 4 levels in Knight.*
12 Daunting Challenge (Ex) – AoE shaken, but by this time, most enemies will be able to easily resist a DC 16 fear effect… If you want to do something like this, try a Never Outnumbered Demoralizer/Intimidate build. You might get a use out of this if you are vs. a horde of weak enemies.
13 Fighting Challenge +3 (Ex) – Still a bad ability. It's basically crappy magic weapon that doesn't always work because monsters aren't smart enough.
14 Improved Shield Ally (Ex) – As shield ally, but on the initial absorb, you take all of the damage instead of half. Subsequent uses still do half, just to spite you. It would be good if there was more control over half dmg. vs. full damage absorb, and I would houserule that in a heartbeat if some masochistic player decided full Knight was what he wanted.
15 Bonus Feat – Take Diehard if you're this far in, the capstone will make it useful.
16 Bond of Loyalty (Ex) – Slippery Mind; you can use a Challenge to save vs. a mind-affecting spell over and over again. Even under the effects of one, you can choose to activate this. Actually a really good use of the Challenge, but it comes available way too late after too many bad abilities. Also, your high will save will hopefully keep this from being necessary.
17 Impetuous Endurance (Ex) – An ability worth of a 17th-level PC: no more failing saves on 1s. Even though you'll still fail anyway. By the way, there are ways to get this at level 1.
19 Fighting Challenge +4 (Ex) – One last slap to the face before one of the best capstones in the game.
20 Loyal Beyond Death (Ex) – Continue to act as long as your body is intact below -10 HP. As long as you have a Knight's Challenge use, you can act for 1 more round before dying. If you get your HP above -10 before running out, you live. Truly bad ass, but comes after along line of just crap. Probably one of the best capstones in the game, but gated by Knight's Challenge, of which you will have maybe 12 or 11 if you've come this far. Definitely pick up Endurance so you can pick up Diehard if you're going Knight 20.
There's two ways to build Knight effectively – lockdown and charging. There's general Feats for a Knight, in both builds, but I'll be dividing them into 3 categories.
Ability FocusSRD – If you really want to utilize Knight's Challenge, you'll probably need this. It's still a waste, though, as the base ability is just that bad.
Ancestral RelicBoED – Good feat if you know you want to keep a certain weapon, and it probably should be a weapon, as your WBL and treasure can be used to upgrade that same weapon. I really like this feat if your DM is scary and might not give you the opportunity to get what you need to make your build work. You have to keep the Family Spiked Chain, after all.
Arcane Schooling – If you're trying to Use Magic Device in order to help your crappy melee class, this can make it easier. Not my style, but someone else might like it.
Blind-FightSRD – It's blind fight, yeah. Helps you do well with your Melee in a variety of scenarios. Not sure if it's worth the competition here, though. Depends on your build and your DM.
CleaveSRD – Knights aren't ever doing enough damage to justify this. Always bad regardless, but worse here.
Combat FocusPHBII – Basically a pre-requisite for better things. Can buff your will save. Horrible by itself. For these to be at all efficient, you need to take at least 3 Combat Form feats, so I've listed the 3 best here.
Combat VigorPHBII – The only thing really worth getting out of Combat Focus. Fast healing 2. Investment is too great to justify, as you also need 13 WIS. Can double the bonus if you have 3 Combat Form feats.
Combat StabilityPHBII – This gives you bonuses to resist all the combat maneuvers except feint. It's a lame +4, but with three Combat Form feats, it becomes a respectable +8. These Combat Form feats need to be taken together in order to be worthwhile, though. Despite that, they are still poor.
DodgeSRD – If you're gonna spring attack, don't. If you're trying to make some ultimate AC build, then LOL.
Draconic AuraDM16 – Choose a Draconic Aura and project it. If you are Dragonblooded, it improves with class levels. Not a bad option, really, but Knights have better things to be doing with their feats.
Dreadful WrathPGtF – Gives you a Frightful Presence that scales with CHA. Only good if you have some CHA, and I recommend that you don't have CHA. Also has weird barriers via setting-based races. If you've got points to burn from being a cheesy lesser-planetouched, this is usable, actually.
KnockbackRoS142 – Best in charger builds, when you power attack and hit, you get a free bull rush attempt that doesn't provoke AoO. You don't move backwards with your foe, also. Probably looks cool, but it is in competition with many other feats. Dungeoncrasher Fighter dip might like this with Charger Knight.
Mage SlayerCArc81 – This is best on lockdown, but you might want it on any Knight if you encounter many spellcasters. For just 2 ranks in Spellcraft (useful in their own right) you can take this feat, get a +1 to Will saves AND Spellcasters in your threat range cannot cast defensively. This means they will always provoke an AoO, which means you can always punish them and make the DC to even continue casting pretty hard. A good spellcaster probably won't let you near them, but for the average spellcasters, this is good. Depending on your campaign this might be a very important feat.
Mounted CombatSRD – A useful feat that you should definitely get for free. Always take at least 3 levels of Knight, can't miss it.
Parrying ShieldLoM181 – Did your DM bully you at level 1 with raging, two-hand greatsword-wielding Barbarians so bad that you had to get a tower shield? Are you now attached to that tower shield? Do you now struggle with monsters touching you with the nasties? This is the feat for you, because if you take it with any other shield it's trash! (Shield AC bonus applies to touch AC).
Power AttackSRD – It's power attack. Essential on Chargers, and good on other builds when you know you can hit. The disabler builds are pretty competitive on feats though, so depending on what kind of player you are you may skip it in those builds. However, a smart player/character can probably figure out when to use this without metagaming too much.
Rampaging Bull RushRoS143 – Combine with Knockback for maximum effect. It's decent, I guess, but you need Powerful Build or to be large.
Mounted Charger Feats
Cavalry ChargerCW108 – There is a maneuver useable as granted by this feat that lets you tack on up to +4 damage on your charge attack for meeting a DC20 Ride check. However, failure means an auto-miss, and failure by 5 means you fall off your mount. This feat can be worth up to 16 damage after charge multipliers, and you get 2 other manuevers which are not as relevant that come with it. Possible choice for a later-game feat, when you know you'll hit the check. Otherwise, it's an all-or-nothing style feat that nets you minimum 6 bonus damage (after multipliers). It's also flashy, and I very much like it. Requires Trample, which does hurt its viability.
Headlong RushRoF164 – The only reason to be an orc/half orc. This causes you to provoke from everyone who can reach your path, including the opponent being attacked. Howevever, you get double damage. Very strong.
Leap AttackCAdv110 – This is vital on chargers, and a great feat in its own regard. Leap Attack requires you to jump 10ft horizontally during a charge, and if you end in a square where you threaten the enemy, you deal double damage that you would normally deal with Power Attack. Basically, Power Attack is a x2 multiplier when wielding with two hands, and this makes it x3. Just a lot of damage that gets scaled up further from charge multipliers.
Pierce Magical ConcealmentCArc81 – Pretty much required to nova-strike endgame enemies with concealment. You don't want to unload a charge and miss. However, if you do, you could just Ride-By Attack and try again if the environment allows it. You do need both Blind Fight and Mage Slayer for this, but it is quite good despite requiring investment, as both the investments are good by themselves.
Ride-By AttackSRD – Basically you keep moving after you make a charge, and can go in a straight line for double your mount's movespeed. Good to charge, hit, and then respace yourself to prepare for another charge. Does not provoke against the target, too.
SaddlebackPGtF43 – A personal favorite, this lets you use Ride skill in place of Ref save once per round for you and your mount. Nice if your DM is a bit evocation-heavy, but there are higher priorities.
Shock TrooperCW112 – Shift power attack penalty to AC is the main function of this feat. Good for once your charge damage multiplier is high enough to ensure a OHKO.
Spirited ChargeSRD – This is absolutely necessary if you're going to charge. It is a straightforward double damage feat when doing a mounted charge. A bonus feat for the knight if she chooses, too.
Tunnel FightingRoS145 – For fighitng in tight spaces without penalty, like small tunnels. This is mainly used to pick up Tunnel Riding so you still fight effectively while your mount is squeezing through a tight space. If your DM is strict about these rules, you should consider this feat if you are a full nova charger.
Tunnel RidingRoS145 – No penalties to fighting mounted while mount is squeezing. See Tunnel Fighting.
Tremendous ChargeDCS – Swap your STR for your mount's on a charge. This is a useful late-game feat for if you acquire an extremely powerful mount. In the mid-levels, this is not so useful, as you will possibly have more STR than your horse or whatever you're riding. It says in the description you can ride a dragon and use this, so if you get a chance to do that… Also, all of your standard feats apply on a charge. This just swaps the STR bonus. Possibly incredible with the right mount. Knights can be part of a supermount build, but there are probably better ubermounts to use with this feat.
Combat ExpertiseSRD– This doesn't see much use except as a pre-req for Improved Trip. Since tripping is a touch attack, you can actually use the improvements to fighting defensively more often than others if you feel so inclined. You can also get more milage out of full defense with this, which is an action you'll never take if you're AoO-based (doesn't allow AoO while total defense).
Combat ReflexesSRD– This is necessary to enable the build. You can live without other things, but this is most important. Probably take at level 1 most of the time.
Deft OpportunistPH – +4 bonus on attack rolls when making AoO. Solid, but worth a feat? Probably not.
Deformity (Tall)HoH121 – For evil Knights, can grant you +5ft reach. This would be black or blue if not for the totally useless prerequisite, Willing Deformity, which has its own obstacles.
Evasive ReflexesToB30 – Instead of an AoO, you can immediately 5-foot step. Good for repositioning. This is best when combined with reach to trap opponents into a no-win scenario.
Exotic Weapon ProficiencySRD – For a tripper, this means getting a Spiked Chain, Kusari-gama, or a Spinning Sword. Those weapons dramatically increase your ability to control the battlefield. This feat is not as useful for a charger, as they can use a Lance by default. If you can't squeeze this feat in, shame, but you can function without it. Using this may make your DM trip you IRL.
Karmic StrikeOA – This seems like a good idea, but it's actually not so good. You must declare that you are using this on your turn, and take a -4 to AC. Anyone who successfully hits you provokes an AoO, and both attacks deal damage simultaneously. This is similar to Robilar's Gambit, but ultimately you are not granted your damage/debuff before your opponent, so it's not quite as good. Also, your AC is lower all of the time – even vs opponents at range. Robilar's is better because it only gives the bonuses to people who choose to attack you in melee. Also it requires Dodge, which knocks it down yet another rank.
Knock-DownSRD – If you deal >10 damage in melee combat, you make trip attack as a free action against the target you dealt the damage to. There is some controversy about this Feat because it is so good when combined with Improved Trip: the combo is use a normal attack, deal 10 damage, activate your trip, succeed on your trip, and attack again for free. Note that the 3.0 version of this feat has errata that prevents the combo, but the 3.5 version on the SRD does not, so it is legal.
Hold the LineShS – Immediately AoO vs an opponent who charges you when it enters an area you threaten. It happens before the charge attack. This feat can be good if you're getting charged a lot or if you have no reach weapon. Even if you do, if the enemy charger has a reach weapon and is not mounted, he will provoke an AoO even withou this feat because he ran through YOUR reach weapon. If you can use Stand Still, you can possibly stop the charge, or just trip them and stop it. Situationally good, but not a priority.
Improved Combat ReflexesELH – No limit to number of AoOs in a round. If you have 21 DEX to get this, then you probably don't need more than 6-7 AoOs anyway.
Improved TripSRD – If you have Improved Trip, you get an immediate attack against an opponent you trip as if you hadn't used your attack for a trip attempt. This doubles your efficiency, allowing you to both damage and disable. Also, since they just got tripped, you get bonuses because they are prone. Also gives a hefty bonus to your STR check when tripping. Essential to fully exploiting the trip build, but completely breaks certain types of encounters. You don't need it to function as an AoO build.
Inhuman ReachLoM – This feat requires you to be aberrant, so perhaps a Changeling could qualify, or you could take another feat to give you the subtype, but ultimately it's not that great just for 5' reach.
JotunbrudRoF – Must be taken at level 1, and is also campaign dependant, but lets you treat yourself as Large when the size modifier is advantageous to you. Does not let you wield bigger weapons, only affects size modifier. You must be a human from a certain region of Faerun to take it, so ask your DM. It's a reasonable Feat by itself, I think most DMs would allow it.
Martial StanceToB31 – If you already dipped a maneuver class, this feat is good to take later to get a high-IL stance, but that's not necessary for the Knight. You want to take Thicket of Blades, a 3rd IL stance which causes ANY movement made by any opponent you threaten to provoke an AoO. Some people debate whether this beats the Tumble skill, but ask your DM. Regardless, it is incredibly useful as it eliminates Withdraw specifically as an option. This synergizes incredibly with Bulwark of Defense, making squares you threaten very hard to escape. You do have to take Martial Study to get this feat, so I recommend a dip into Crusader instead, as it saves you Feats and nets you tons of useful other things. The other stance you might get later is IL5 Dancing Blade Form, which grants 5ft reach only on your turn.
Martial StudyToB31 – A decent situational feat if used well in the build, as it gives you a class skill from the discipline (permanently), and any maneuver you have the IL to support. So, if you take this feat at a high level, you can pick from a pretty huge selection of maneuvers. However, this feat is extremely inefficient depending on which maneuver you want, so it’s probably best to just dip Crusader and get the benefits of this feat directly. Generically good maneuvers: Iron Heart Surge, White Raven Tactics, Stone Dragon/Mountain Hammer line of maneuvers (bypassing DR), Shadow Jaunt (standard action tele), Diamond Mind Fort/Ref/Will save counters, and Burning Brand (bonus reach).
Robilar's GambitPHBII – This feat allows you to completely cover an opponent in your threat range's options, barring a teleport that doesn't provoke. As a Knight, you will threaten at the very least the squares at 10ft reach. They will be difficult terrain, and your opponent cannot 5-foot step away from you. They cannot Withdraw or Tumble if you have a Spiked Gauntlet to threaten the squares adjacent to you. They are forced to run away normally, provoking an AoO which either trips them or stands them still. This feat causes their only other option, attacking you, to also be a chance to hit them with an AoO. They will, however, probably hit you, but since they will be prone from your AoO, the +4 to hit from Robilar's Gambit will be negated. That's why this feat is good. This stance does not technically overlap with a ToB stance.
SidestepMH28 – This WOULD be an amazing option, but it takes 8 ranks of Tumble, Dodge, and Mobility. There's just not space for those in a good build.
Short HaftPHBII82 – Sounds like a good deal, but is a trap. This lets you burn your swift action (which you have other uses for) to give up reach on your reach weapon so you can hit somebody next to you. Also it requires Weapon Focus, and removes your ability to regain reach until you use ANOTHER swift action. Honestly, the goal isn't to hit your opponent anyway, it's to entice them to hit YOU and make it a bad choice to run away. If they are adjacent, that's a good thing. If you don't like not being able to hit adjacents, get a Spiked Gauntlet or use the feat you were going to use on this to get EWP for Spiked Chain and beat the game. One of the most annoying bad Feats in the game, since it is just so blatantly a trap.
Stand StillSRD – As an alternative to tripping, you can give up your AoO when an enemy leaves a square you threaten to try and stop him from leaving. If you hit your attack, he has to Ref save vs DC 10 + YOUR DAMAGE. If you succeed, they stop moving, loses his move actions, but take no damage. This becomes less effective as levels increase (melee damage devalues) and Ref saves improve. If your foe is already tripped and crawling away, this is a great way to disrespect them. If you're not taking Combat Exp and Imp Trip, then this is a good substitute.
Weapon FinesseSRD – Well, for some reason you can use Weapon Finesse on a Spiked Chain. If you're just trying to hit your enemies with AoO for damage, but not trip them, Weapon Finesse is a good choice, as it makes you less MAD. You will deal less damage though with each strike, but you will be more guaranteed to hit. You can eventually invest in a ToB feat that lets you add DEX to Damage if you're really concerned, but it's a bit of an investment. Don't take Weapon Finesse if you want to trip, though, as you'll still need STR to beat them and trip them. The Setting Sun maneuvers can let you use DEX or STR to trip, throw, etc. if you decide you need the occasional trip in a Finesse build.
Weapon FocusSRD – If you know you’re not going to have to change weapons, this is tolerable but I don’t recommend it at all except as a pre-req for something else.
Whirlwind AttackSRD – Too many pre-requisites. Might be cool otherwise.
Willing DeformityHoH125 – Requires you to be Evil-aligned, and gives a cruddy bonus to Intimidate. The only reason you would take this is to get to Deformity (Tall).
Wolf BerserkerUE – A cheesy feat that is basically better Combat Ref. You have to be able to Rage and be a member of some organization (which does not exist in the campaign world if you DM says no), but it gives you +4 on trip attack and +4 to resist trip. Probably not realistic to use.
Skills & Skill Tricks
Knight skills are extremely straightforward. You should be doing your skills this way pretty much exactly.
Appraise – 0 points.
Autohypnosis – Not enough skills to invest in the non-psionic uses.
Balance – With 5 ranks in balance, you are not considered flat-footed while balancing. 0-5 points.
Bluff – Evil knights only.
*Climb – Too situational, and you'll have a good strength score to make up for it.
Concentration – 0 points.
Craft – 0 points.
Decipher Script – 0 points.
Diplomacy – If you play with the Knight's code, you might need this, but you won't be good at it.
Disable Device – Too costly/difficult for a Knight.
Disguise – Not needed.
Escape Artist – Too situational, should use your STR to escape instead.
Forgery – 0 points.
Gather Information – On the off-chance you have CHA, this can be a cross class pickup.
*Handle Animal – Get 5 ranks in Handle Animal minimum for the bonus to Ride. Knights and any derivatives don't have the skill points to invest enough to train their own animals, but luckily you can buy trained mounts or get a special mount through multiclass and prestige.
Heal – Only in the most extreme cases should this be considered.
Hide – Not stealth character.
*Intimidate – Better than the other social skills to invest in, but still not good. The best one a for a Knight, as it's his only social class skill. Very sad that Knights do not have diplomacy as a class skill. You can do fear builds with the Knight and they can synergize with your Challenges.
*Jump – 8 ranks absolute maximum, for Leap Attack or canceling armor check penalties. Your STR will be able to yield you a good jump check, yet I find jumping more common than climbing or swimming, and if you need to jump, you probably need to do it now. You can and probably should ignore jump, though.
*Knowledge (nobility and royalty) – Put 1 point in to get the skill use. Probably the least important knowledge, but it's all you've got. May not even be applicable to your campaign, so possibly you need 0 points. At best, you might have +1 INT from Combat Expertise.
Knowledge (religion) – A good knowledge, and possibly useful if you are taking a Vow or something. Religious knights are common flavor, too.
Knowledge (everything else) – Not enough skill points to invest in them.
Listen – Put points in spot instead, don't have enough for Listen.
Martial Lore – If your campaign has initiators (from ToB) you may want to put a point in this.
Move Silently – Not stealth character.
Open Lock – Better luck hitting it with your face.
Perform – No.
Profession – A Knight is already profession, I thought?
*Ride – One of your skill points should go in this skill every level. Even if you are going to be a lockdown build, you can ride a warhorse while you do it to give you more reach and better defenses. Get points in Ride and get a warhorse!
Search – 0 points.
Sense Motive – Useful but no way to invest.
Sleight of Hand – Not a stealth character.
Spellcraft – 2 point maximum. Used for access to Mage Slayer exclusively.
Spot – One of the best skills in the game. You really don't have room to invest in it, but if you do it is a damn good skill.
Survival – 0 points.
*Swim – Don't bother swimming, try to avoid getting in the water in the first place. The Armor Check penalty is high for an armored character, which you may be, and your STR will help you to swim if you absolutely must.
Tumble – Even with the DEX to support it, you won't be wanting to tumble about. This can be used for Twisted Charge, though, a decent skill trick.
Use Magic Device – Good skill, no room to put points in it. Maybe a few here and there to get a wand of Enlarge Person or something?
Use Rope – Bad skill, no room to put points in it.
Extreme Leap – 5 ranks of jump, you can use swift action to get 10 feet bonus on a 10 foot or greater horizontal jump. If you are like me and invest a little in jump, you might want this later to surprise your foes or clear a gap to safety. Situational, though, so not that good.
Nimble Charge – 5 ranks of Balance, you can run or charge over difficult terrain without making a Balance check. Chargers should just jump over difficult terrain, and will be jumping to utilize leap attack, but I can see taking this if you can't jump for some reason, like a cave or something.
Twisted Charge – 5 in balance and 5 in Tumble let you turn 90 degrees during charge movement once. I'm not sold on it, as the investment in Tumble is really tough sell. However, some people like it.
Knights are a horrible class choice for ECLs lower than 4 in terms of power. At levels beyond 3, Knights are a solid addition to a melee build and can stand alone as a primary class until level 11 or so. Dips with bonus feats (for lockdown more than charger) or abilities that help the charger are the primary focuses of multiclass Knights. However, Knight is generally the class being dipped as part of another build, so there will be a lot of options here.
Fighter – No joke, 2 levels of Fighter is a very good idea for the Knight. She gets 2 levels of Fort saves, 2 free Fighter Feats that she can definitely use, and full BAB. Just because of how good Feats make Knights, this is a high tier choice for all Knights. The most straightforward boost in effectiveness, uncomplicated by a lot of things, and for this reason for most players this is the gold option.
Dungeoncrasher Fighter – This ACF replaces the 2nd and 6th levels of fighter with an ability that lets them bull rush enemies into walls for 4d6+2 times STR mod. They also get more AC and saves versus traps. This is a great ACF if you plan to utilize some crazy Knock-back and Shock Trooper combos to beat enemies up. It's another variant of a lockdown build that utilizes bull rush instead of trips, and it can deal loads more damage, but requires more investment.
Warblade – Not as good as Crusader, but offers the Iron Heart line of maneuvers, including the awesome defensive Iron Heart Surge. Considering the role of a lockdown build, that is attractive as an option. This class also has some maneuvers which can do more damage on trip and whatnot. It also has awesome counter moves, which is good because as lockdown enemies will often choose to try and kill you instead of run. Just an all-around good dip or addition to any Knight. The ToB classes favor lockdown, but you can certainly make use of them in a charger.
Swordsage – This class doesn't have full BAB, but it does have a lot of access to mobility maneuvers and Shadow Blade. Why you would use Weapon Finesse though is beyond me, as you need hella STR to win trip and bull rush. Still, this class is a martial initiator, so it's never a bad dip. This class also has some maneuvers which can use your DEX and STR mod for damage on throws and other odd things in the Desert Wind discipline.
Crusader – So many options for a Lockdown build. Usually, Crusader is the primary class with Knight as the dip, but you can just dip Crusader for the good bits, like Thicket of Blades or White Raven Tactics. This class is very teamwork-oriented on paper and has good HD, BAB and defensive options in the delay damage pool and misc. maneuver.
Barbarian – Get pounce with 1 level of Lion Totem Barbarian. Amps up your damage on a charge by a lot. Very important dip for a charger, pretty much essential. In other ways, a Barbarian dip can be effective if you want rage or something, but it doesn't give a lot of features that can help you besides stats.
Marshal – Synergy if you are using CHA in your build. For a lot of plain Knights, the synergy you can get from multiclassing with decent CHA can be sort of fun if you aren't too worried about power. Marshal gives CHA bonus to STR checks for just 1 level investment, to you and your party. An awesome dip at lower levels.
Paladin – There's theoretically some great synergy here, as the Paladin gets a special mount at level 4. A direct hybrid of these 3 classes can be great, and could make investment in CHA actually worth something. Good choice for non-lockdown Knights or generic knights. Chargers can start building a supermount here. Requires a lot of levels, though, and not really best as a dip.
Sorcerer – If you absolutely want some sort of spell, there are ACFs and variants of this class that give better hit dies and combat ability. They scale off of CHA, which you should be dumping but whatever, it's your life.
Cleric – A 1-level cleric dip can net you Devotion feats or Domain powers. You do lose 1 BAB, but do gain some good saves, though. The Domain powers and Devotion feats that replace them that may interest a knight the most are:
Charm – untyped +4 to CHA for 1 min as a free action. Huge boost to Knight's Challenge.
Darkness – Blindfight bonus Feat (can get access to Mage Slayer faster)
Baator – perfect vision in all darkness
Earth Devotion – you ignore difficult terrain 1/day immediately, or make difficult terrain (synergy with Bulwark)
Animal Devotion – sacred bonus to STR, fly, run faster, bite, x/day.
Travel Devotion – basically pounce without the charge. (for lockdown builds that need to haul ass)
There are a few especially good good prestige classes for a Knight.
Ashworm Dragoon – Some odd requirements (you have to find and ride an ashworm) aside, you'll have both of the necessary feats and skills with Knight alone. This class has a lot of generically good abilities: unlimited Mounted Combat uses, a special mount that scales with class levels, and you can burrow with your mount in some types of ground. You can take as many levels of this class as you feel, but I recommend 7 to get Full Mounted Attack, which lets you basically move and full attack. For a charger, this is not as necessary, because you should just get pounce, but for a lockdown build, this can be great repositioning tool.
Hellreaver – Easy entry. Has synergy with charisma and a big hit die. You can enter a state of Holy Fury which gives you points that scale with charisma, you can spend holy fury points to either heal yourself or deal damage. If you invested in Charisma for some stupid reason, then you could take this class to get a bit of mileage for it. Also gets mettle at level 4, pretty early. Good for a brief dip to get the main abilities. Has crummy saves, so max of 4 levels IMHO. Not good for chargers or lockdown, only traditional Knight. Most of the stuff only works versus evil-aligned foes, though.
This is a small selection of the most powerful equipment for certain builds. This list is not comprehensive; generic items that boost stats/saves are not going to be listed, but items that give special abilities which enable a class to do better or accent some ability.
Lance – All Knights buy a lance at level 1. Hell, it should come free with the class. If your Knight doesn't have one, go get one immediately. TRIPLE DAMAGE ON A CHARGE. REACH. AHH!
Spiked Chain – AKA the Cheeze Chain. The best melee weapon in the game. She can threaten/attack adjacent as well as within her reach. This is the preferred weapon for dedicated lockdown builds as it deals more damage, more consistently, and requires less positioning effort. If you're mounted you threaten as if you're large, so you threaten everything within 2 squares of your mount.
Spiked Gauntlet – Cheaper than short haft, and costs less actions. This is great way to compensate when you don't have the Feat to spare for a broken reach weapon like the spiked chain. If you buy a Spiked Gauntlet, you can technically hit targets both adjacent to you and at reach range with any reach weapon.
Spinning Sword – Cheeze Chain Jr. He's a 1-handed variant of the Spiked Chain, dealing less damage and can be worn as a belt to conceal it. Requires EWP. Why do you care about this? As a Knight, the Shield Ally ability, which is decent, requires a shield. Also, a shield can boost your AC, which can be in question if using Karmic Strike/Robilar's after taunting a bunch of enemies on yourself. Less effective
Kusari-gama – The one-handed Spiked Chain, but also a double weapon. Also, your damage goes down. Requires EWP.
Greatsword – Best weapon for consistent DPR. Not really for the Knight, who won't excel at dealing damage without support from his Lance and a mounted charge.
Longsword – The weapon that goes with sword & board style Knight. A good choice, but if you're interested in less lethal options this is not ideal.
Truncheon – 1d8 nonlethal bludgeoning martial weapon. Perfect for a Knight who keeps screwing up the code in the face of an unmerciful DM. Eventually you can use a real magic weapon with the Merciful +1 bonus, but if that's not an option, the Truncheon is here for you.
Guisarme – The best martial tripping weapon imho. It has reach, but you can't hit adjacent enemies. Your combos will still work though if you keep them adjacent to you, but you won't be able to deal nutty damage like with a spiked chain.
Whip – A whip is a pretty crappy weapon, to be honest. It doesn't deal damage hardly at all, but it does have 15ft of range. If you want this for flavor or a specific bull-rush/trip build, go ahead, but a Knight has the durability to at least use a Guisarme or something at the cost of zoning. I don't prefer it, personally.
Composite Bow/Crossbow – Good to have if you can afford it, and if you invested in some DEX for AoO you might not suck at hitting.
Spiked Heavy Shield – If you're using a shield, why not give it some spikes? Well, I can think of a few reasons, but that doesn't matter. Spikes are cool.
Merciful – Constantly taking -4 to attack targets nonlethally getting you down? Well, fear no more. This +1 is a ripoff that makes all weapon damage nonlethal and adds 1d6 damage. Horrible normally, but with bad classes, sometimes bad options might be good.
Sizing – This lets you change the weapon size as a swift action. You can shrink your reach weapon to 1 size category smaller and attack adjacent enemies with a -2 penalty, as reach weapons smaller than your size category do not function as reach weapons. Less cheezy than the Spiked Gauntlet method, and preserves more damage, since your weapon with probably be magic and your gauntlet will be plain. Pretty wasteful, still.
Speed – Extra attack on full attack. Doesn't stack with Haste. Charge and pounce.
Whirling – Gives you whirlwind attack as the feat 3/day. Since the Feat chain is like 5 feats too long, and this only costs +1, it's a steal, especially if you've got some serious reach and punishment.
Valorous Weapon – Oh boy, did someone order some damage? This makes a weapon deal double damage on a charge. It's also only +1. Yes, charging did get even easier. Yes, this does stack with Spirited Charge and the Lance's innate bonus.
Sweeping Weapon – For trippers. +2 competence bonus on STR check to trip. +1 modifier. If you're hurting for STR vs some bulkier enemies, this is a good pick.
Paralyzing – Save or be paralyzed on hit. Every round the struck target must try to save again. Could be decent on a defensive lockdown character.
Sudden Stunning – Save DC that scales with CHA stuns enemies. Pretty good for how cheap it is, and if you have invested in CHA at all like the class intends, you can make use.
Gloryborn Weapon – 600gp for +1 damage on a charge. Munchkin-only.
Charging – 2d6 extra damage on a charge for +1. Worth it, but the damage is static.
Vampiric Weapon – Steal some health on hit. Not my style, but is effective sometimes.
Animated Shield – Awesome thing to get for a lockdown or regular Knight. You get all the benefits of shield without having to use a hand to wield it. You can get the superior 2-handed fighting style without giving up Shield Ally or the AC bonus.
Retributive Amulet – Send 1/2 melee damage taken back to the attacker. Perfect for Karmic Strike/Robilar's Gambit, as eventually people will start hitting you and you will want to punish them.
Armbands of Might – Standard melee armbands. Bonus on STR checks and extra damage if you power attack. Good, but generic.
Bracers of Opportunity – Basically gain a +2 bonus on AoOs if you have combat reflexes, and +2 extra AoOs per day, granted by an immediate action, though. Very good in low-dex AoO builds, as it's hard to keep good STR and DEX.
Greatreach Bracers – Extend reach by 10ft for 1 round as a swift action. Good for grabbing people who somehow manage to escape, especially with a spiked chain. Strong on AoO builds.
Strongarm Bracers – Classic melee bracers for damage-dealers that let you use weapons 1 size category larger. This does not expand reach, but does stack with Powerful Build, so you can use huge weapons. However, there is some competition for this slot, so choose wisely.
Boots of the Battle Charger – These let you charge as a standard action 2/day. So you move after a full attack pounce and charge again. Full attack as a standard action. Quite the cheesy loophole. Well, these are good, but some chargers will deal so much damage later that they won't need to use them to reset their position after a charge. They'll just go for the next enemy. A good item nonetheless. Still cheesy.
Boots of Speed – Haste 10 rounds a day. Squeeze in an extra attack on the charge, I suppose. Pricey, but that's because it's a free action to activate.
Riding Boots – treated as having Ride-By Attack. If you have Spirited Charge, the damage multiplier on a charge increases by 1 when using Ride-By Attack. This makes it less good, as you cannot pounce, but these are still a solid item. Also, untyped bonus to Ride skill.
Rule of Doubling – If you double damage, then double it again, it is not quadrupled. It is tripled. If you double triple damage, it is a quadruple. If you double quadruple, it is quintuple. Basically, x2 and x2 are x3. So x2 and x3 = x4.
Weapon Damage Doubling – If you double the damage from a weapon, you do not double other damage dice, even if those damage dice are applied with the weapon. You can double your STR bonus, power attack bonus, and anything else applied to the weapon's attack, but not extra fire damage dice from a magic weapon or buff effect. When in doubt, remember that extra dice are not doubled.
Mounted Reach – When mounted, you occupy all of the squares your mount occupies. This does not mean that you threaten as if you are standing in each square, but that you now are large, basically. Thus, if you have a Guisarme, you threaten everything 2 squares (10ft-5ft) away from the mount. Your mount threatens whatever area it threatens separately. You do not get to threaten adjacent squares with a reach weapon while mounted by virtue of inhabiting all 4 squares.
Special thanks to Person_Man for their original Knight handbook.