Tables for how much experience is necessary for achieving level gain is available under each class listed in Player Characters.
Experience is gained, first and foremost, through the causing and taking of damage. To promote risk-taking and because I believe suffering is more enlightening than success, the greater balance of experience is gained from taking damage than from giving it. Moreover, the system includes a substantial award of experience for seeing others take damage, even if the combatant takes no damage themselves. Because there is a rule that states a combatant must take part in a combat to enjoy this bonus experience, the group gain from individual effort tends to encourage parties to act together, willingly taking a hit for one another.
- For each point of damage that a combatant receives, they are awarded 20 x.p.
- For each point of damage that a combatant causes, they are awarded 10 x.p.
- The total of x.p. damage that has been received by all the combatants on a given side are added together and multiplied by 20 x.p. This bonus is then shared out to all combatants who have participated in the combat.
Participation in combat is defined by having attempted to hit an enemy with a weapon or having been a defender where damage may have resulted from an enemy's attempt to hit. This may seem extremely minimal, since it does not actually require that the combatant have any influence over the battle at all.
Participation in combat is defined in two ways:
- By the combatant's attempt to hit an enemy that can be hit. If the enemy's armor class or defenses preclude any possibility of success, then participation cannot be demonstrated in this way. Actual success is not required - only attempted success.
- By the combatant putting their body in the way of an enemy's attempt to hit that combatant. Actual damage received is not required - only the potential that damage may have occurred.
This may seem a minimal involvement, but participation is defined as such because it serves the game, especially for lower level characters joining a high-level party. Since it allows the player to assess the risk to themselves while standing to gain a substantial bonus from higher level characters taking considerable damage, it helps balance out the lower level's ability to gain levels through witnessing very powerful combatants act in a magnificent fashion.
If it should happen that a player would attempt to take advantage of this rule, then it is reasonable to expect the remaining party to deny that player any share of the treasure that follows, or indeed to discourage that particular player to leave the campaign altogether. Creating rules that deny players opportunities for being cowards is not nearly as effective a containment measure as enabling players to decide what sort of people with whom they'd like to play.
See Experience Solved.
Magic ConsiderationsThere are a number of magic spells that are easy to adapt to the above system, as they cause specific damage to a single target: magic missile, Melf's acid arrow, cause light wounds, fire trap, etc. Such attacks award 10 x.p. per point of damage caused, just as an attack with a weapon would.
Because there are certain spells that cause damage to multiple targets without there being any more effort than it takes to cast a single spell, a slight adjustment to the rule must be made. The total of all damage done to all targets is added together and each point of this total awards the spellcaster 3 x.p. per point of damage caused. This rule applies to area-effect spells such as burning hands, fireball, wall of fire, blade barrier, cone of cold, etc.
If a spell causes death to a combatant, thus removing all their hit points, then the spellcaster is awarded 10 x.p. per point of hit points that the dead combatant possessed. This applies to spells such as phantasmal killer, power word: kill or death.
If a spell increases the combat power of a given combatant through supplying them with equipment, additional abilities, size and so on, then the spellcaster is entitled to 10% of the total experience from damage that the affected combatant causes. Similarly, if a combatant is created that causes damage, the caster is again entitled to 10% of that damage as well. This applies to spells such as enlarge, monster summoning, summon elemental, etc.
If a spell gives a bonus to damage that can be tracked specifically, by its adding 1 or more specific damage to every hit, then the spellcaster is entitled to the experience gained from this bonus damage. Thus, if the spell chant gives a bonus of +1 damage to the attack of every friendly combatant, then each time that extra damage is caused, the spellcaster receives the 10 x.p. award for it. This applies to spells such as chant, prayer, strength, flame blade, etc.
Finally, there are various spells that do not provide an x.p. bonus, though they affect the combatant's attack or defense. Partly this is because of the difficulties in tracking the damage done, but largely it must be understood that casting a spell is very often not a risky action for a spellcaster. This is especially true of spells that can be cast well ahead of a battle, such as bless, armor, phantom armor, barkskin or stoneskin, etc.
Experience for AchievementOn the whole, I am against giving experience for achieving goals, particularly short-term goals. Moreover, I feel it is impractical to reward with experience actions which in no sense would contribute to a character's fighting skill, such as talking a monster out of an aggressive act or negotiating for something as opposed to fighting for it. I feel these things provide their own reward, without adding experience.
However, I do believe that major achievements - the conclusion of quests that may require more than six months of sessions to complete (around 13-20 sessions) deserve a benefit for all those who have taken a role. For such events, rather than giving out experience as a set amount, I prefer to let the players know that all their characters should increase their experience a flat 5%, 10% or 20% across the board, depending upon the amount of difficulty or time taken to complete the quest. Using a percentage, everyone, regardless of level, gains an appropriate boost to their experience based upon their level - so that the 9th level gains as much as the 3rd level.
See Attacking in Combat