In my campaign, knights are generally field officers/special forces. The original order of knighthood came as part of an alliance of three nations who organized their forces into one larger military unit that still exists to this day as the Knights of the South. It would be equivalent to a modern day UN peace-keeping force. Most of the KotS are regular troops generically called knights, but the actual number of real knights in the force is quite small (the official term is Knight-Commander).
Beyond that, each nation has its own knightly order to lead troops into battle. Among the middle-eastern like Randese, these knights are known as Saracens. Among the magic-wielding Silka Kingdom, they are called Chevaliers, among the spanish-like Millese, they are dubbed Musketeers.
Each order has its own rules and regulations, but most knights are wealthy aristocrats - it takes money to maintain the weapons and gear of a knight and live life as a soldier instead of working in the fields. Likewise, many landed knights (knights who do own land) also are charged with providing warriors for the country they defend should war break out - and arming, feeding and housing said individuals takes money.
There are also those knights who receive their commission on the field of battle. These knights may be commoners or freemen given this honor for extreme acts of heroism. Generally they don't have the funds to maintain more than themselves and their own gear, and they are often known by the term "knight errant". Knight errants have obligations to show up for battle if called by their lord, but otherwise spend their time performing tasks to hone their fighting skills and otherwise earn money/food and the like by "questing" or performing mercenary work.
Likewise, the knightly codes vary from country to country. Some examples of the vows and duties of the various counties in my game are:
Knights of the South/Southern Kingdom/Unaligned realms (Lawful Neutral, Lawful Good)
- Honor and Bravery both on the field and off
- Humility in one’s actions
- A knight’s actions and words should act in concert
- A knight’s word is his bond
- The knight defends the innocent and helpless
- Evil cannot go unpunished
- Mercy to enemies who ask for it
- A warrior has the right to die in honorable combat, face to face with his foe*
- Knight’s weapon: Long sword, bastard sword, two-handed sword, lance, morning star, spear, halbard
* Knights of the South frown on the personal use of ranged weapons, but will not punish others for their use.
Kingdom of Vall Vega (Lawful Neutral, Lawful Good, Lawful Evil) and allies
- Humility in one’s actions
- Lawbreakers must be brought to justice
- Mercy to enemies who beg for it
- Ranged Weapons are the weapons of coward.*
- Knight’s weapon: Long sword, bastard sword, heavy mace
* Knights of Vall Vega generally kill enemies who use ranged weapons against them. They do not allow the use of ranged weapondry among their ranks (though they will field mercenary archers when facing foes known to use ranged weapons), and have great disdain for those they affiliate with who do use them.
Llannhanex/Iiannhanex (Lawful neutral)
- Fearlessness on the battlefield
- Lawbreakers must be brought to justice
- The defeated and all his possessions are the lawful property of the victor
- Mercy is a virtue to be doled out as appropriate
- Loyalty to the country and its leaders
- Knight’s weapon: Khopesh, camel sword, scimitar, scorpion sword (Llannhanex only), spear, sling, short bow, long bow
Llannhanex/Iiannhanex regularly use ranged weapons before closing into melee combat. Some knights prefer the use of ranged weapons and chariots, never closing to melee.
Millos (Lawful Neutral)
- Personal glory in combat elevates one rank
- Cowardice on the battlefield is unforgivable
- Any weapon or tactic to defeat an enemy is fair, though stealth and ambush are the tools of the weak
- Mercy for those who can pay for it
- To the victor go the spoils
- Knight’s weapon: Rapier, long sword, pistol, longarm
* Millos knights prefer pistols and long swords for war and rapiers for personal combat.
Misake/Barbed March/Principalites of Xatmas (Lawful Neutral, Lawful Evil)*
- A trial of arms cannot be refused
- A victory by an means is better than defeat
- Honor and integrity when dealing with a foe (off the battlefield)
- No wrong can go unpunished
- Mercy is for the coward and weak–willed
- Death in combat is the fate of the warrior – fleeing a combat or refusing to face an enemy is shameful
- Knight’s weapon: any
* Misake/Barbed March knights use ranged weapondry when closing with an enemy, then prefer to melee. Staying at range is frowned upon and can result in charges of cowardice (and execution or defrockment).
Randu/Skienlands/Simera/Ran Da Khan (Lawful Neutral, Lawful Evil)*
- Only divine magic and the magic of the Wa–Atari/Wri–Atari is sacred – all other spellcasting is an affront and must be punished
- Loyalty to the home country above all else
- Spells are the tools of the weak and should be avoided.
- Mercy to those who have proved their mettle in combat
- Knight’s weapon: Scimitar, falcion, short bow, spear, halbard
* Randese knights commonly use ranged weapondry and do not frown on its use
Silkna Kingdom (Lawful Good, Lawful Neutral)
- Those who wield magic have the right and duty to rule
- Evil cannot go unpunished
- Mercy to enemies who beg for it
- The weapons of war are varied; there is no shame in the use of any implement of war*
- Knight’s weapon: Short sword, long sword, two-handed sword, handaxe, battleaxe, greataxe, lance, spear, heavy mace, heavy flail, sling, crossbow
* Knights of the Silkna Kingdom have no compunction against using ranged weapons or spells to defeat an enemy, but consider poison and other “terror tactics” to be out of bounds
Spi Dak Su/Chiamung (Lawful Neutral, Lawful Evil)
- Those who wield their weapon in the name of their lord are also entrusted with the dispensation of justice against the common populace
- Loyalty to one’s lord above all, and to the emperor above one’s own lord
- One on one duels are the true test of the warrior
- Once war against an enemy is declared, all tactics are fair game
- A warrior does not strike a foe without warning
- Mercy is for those unable to accept the fate of the defeated
- Knight’s weapon: Katana
* Spi Dak Su/Chiamung warriors have no compunction about using ranged weapons, poison (but never on a katana) or magic to defeat an enemy, as long as such use is not done secretly or from ambush.
Lastly, what do you get by being a knight:
- A small sum monthly or yearly to pay for your gear (and loyalty)
- The right to be called "Sir" or "Madame" (or it's equivalent)
- The right to bear arms and wear armor in public without restriction
in your home country (i.e., no peacebonding of weapons or banning of weapons from public areas)
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Most countries grant you the power of a law officer - you can arrest, act as a judge over squabbles among commoners and in some places/cases mete out justice to lawbreakers
- Demand shelter/food/goods from commoners to fulfill your duties; you can request food/shelter from nobles while engaged in knightly duties
- You are allowed to maintain a keep or other stronghold and in some cases, organize and maintain a small military force or garrison for times of war.
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