There are many ways to gain XP, the easiest is through good old fashioned rock-'em-sock-'em action. You gain XP for defeating villians (if you are a hero) or defeating heroes (if you are a villian). This is general, for instance, a Chaotic Good character and a Lawful Good character may fight eachother, because, even though they are both good, they may have vastly imcompatable views of justice. For example, if the Arcane is seen by Phterots killing a villian (Justified by the Arcane, because allowing evil to exist is in itself a worse form of evil.), Phterots will attack the Arcane for his actions. (Justified by Phterots in that Exodus 20:13 says "Thou shalt not kill.")
If you win a battle (i.e. knock a character unconcious) you gain experience. The experience you gain is porportional to the difference between your combined level and their challenge.
Your combined level is the average of the group rounded down. Thus a group of 1 level 4, 2 level 2's and 1 level 1 would have a combined level of 2. Your Level:
1-3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20
If there is no number listed it is because a) it would be suicidal to attack an individual or group that powerful or b) it would be so easy to defeat an individual or group that the XP is negatable.
The other way is by acting like a hero or villian. In the case of mercinaries, you act as your contract would have you act.
Note: The following are bonuses in XP for Heroic actions. A character can never drop below 0 XP. If they drop levels they retain their power levels, but, must work their way back up to the level from which they dropped +1 to gain anymore power. Thus, if a 10th level character drops to level 7, he would need to reach level 11 before he gains any more power. Obviously, you can't just walk up to someone on the street and arrest them for a crime they had nothing to do with and expect to get XP.
Prevent a suspect from commiting a violent crime - 30
Arrest a suspect of commiting a violent crime - 15
Prevent a suspect from commiting a destructive crime - 20
Arrest a suspect of commiting a destructive crime - 15
Prevent a suspect from commiting a violent crime - 30
Arrest a suspect of commiting a violent crime - 15
Prevent a suspect from commiting an act of robbery - 20
Arrest a suspect of commiting an act of robbery - 10
Prevent a suspect from commiting an act of armed robbery - 30
Arrest a suspect of commiting an act of armed robbery - 15
Prevent a suspect from commiting a victimless crime - 20
Arrest a suspect for commiting a victimless crime - 10
Preventing a misdomenor - 5
Arrest a suspect of a misdomenor - 5
Prevent suspects from commiting an act of conspiracy (local) - 20
Arresting suspects for commiting an act of conspiracy (local) - 10
Prevent suspects from commiting an act of conspiracy (regional)- 80
Arresting suspects for commiting an act of conspiracy (regonal) - 40
Prevent suspects from commiting an act of conspiracy (national) - 320
Arresting suspects for commiting an act of conspiracy - (national) 160
Prevent suspects from commiting an act of conspiracy (international) - 1280
Arresting suspects for commiting an act of conspiracy (international) - 640
Definitions:
Destructive Crime - Any crime which destroys or seeks to destroy property. Examples are arson (if no one is killed), and breaking and entering (if nothing is taken).
Violent Crime - Any crime which destroys or seeks to destroy a human being. Examples are murder, rape and assault.
Robbery - Any crime in which the property of another is taken without their consent. Examples, shop lifting or pick pocketing.
Armed Robbery - Any crime in which the property of another is taken without their consent under a threat or precieved threat of physical harm. Examples, holdups or muggings. (Note: By this definition, putting your fingers under your coat as a gun and entering a bank is considered Armed Robbery.)
Victimless Crimes - Any crime which while illegal harms only the criminal or those willing to pay for the criminal act. Examples are drug use (until there are drug related homicides in which case it is also a violent crime additionally.) or prostitution.
Local Conspiracy - A consipiracy involving a single local and the ramifications of which signifigant are only locally. An example would be conspiring to rob a bank or an attempt of the Mayor's life.
Regional Conspiracy - A consipiracy involving a region. and the ramifications of which are signifigant only regionally. An example would be conspiring to rob a series of banks in the American South or an attempt on the Governor's life.
National Conspiracy - A consipiracy involving a nation and the ramifications of which are signifigant nationally. An example would be conspiring to rob the United States federal reserves or an attempt on the President's life.
International Conspiracy - A consipracy involving the world and the ramifications of which are signifigant to the planet. An example would be conspiring to rob from the IMF or blowing up the U.N. building.
If you fail to prevent a crime (when you could), you lose as many XP as you would receive for an arrest for this type (i.e. you would lose 15 XP for failing to stop an armed robbery. If you commit a crime, you lose XP at double what you would gain for preventing it. (i.e. you would lose 60 XP for commiting armed robbery.) If you are honor bound (Any Good and most Lawful Evil) and you commit murder or through your in action allow an individual to die you drop one level. When you drop you go to the beginning of the previous level. If you are level 1 you lose all XP.
For villians, they get an XP bonus equal to the XP bonus the hero gets for preventing a crime if they commit a crime and are successful, if they are foiled they get the award of XP given to the hero for an arrest. An honor bound villian (most Lawful Evil characters) get the same penalty as Heroes for murder. A non-honor bound villian (Neutral Evil and Chaotic Evil characters) gets 10 XP for murder (this is in addition to bonuses for commiting a violent crime).
An act of selflessness which results in:(Must be done in tune with character) -
Your character being wounded (obviously a paper cut won't cut it) - 50
Your character being maimed - 200
You character's death - 1000 (posthumorously)
For above use logic, a soldier throwing himself onto a gernade to save his comrades is a noble act, a hero blowing himself and the villian (along with 40 others) up, just to kill the villian is not.
Be warned, most heroes and almost all villians are not immune to the long arm of the law.