Experience points, commonly shortened to EXP or XP, are an element in most role-playing games. When enough experience points are obtained, the character will increase in level by at least one, or "level up", which usually increases the stats of the character in some fashion, and may also add new functionality to the character, such as new skills, or abilities.
Usually, the amount of experience points required to level up, and/or the difficulty in obtaining experience points, is higher for higher levels than lower ones, so players who simply repeatedly defeat low level enemies or complete the same quest over and over don't end up increasing in power incredibly, thus encouraging players to continue the main storyline of the game to continue gaining strength.
In some games such as the first Breath of Fire game, the amount of EXP earned in a battle is split across the party members who took part in the battle, causing larger parties to gain a reduced amount of experience, while other games will give the same amount of EXP to all party members regardless of how many members took part in the battle, so the player is not penalized on the size of the party. Some games, such as Final Fantasy VII, do a mixture of the two, giving the normal amount of experience to characters who participated in the battle, but also giving a smaller percentage of other characters, so that if they're suddenly required to be in the party, or another character is ejected and that character is sent back in, the character is closer to the level of the higher leveled characters.
In RPG Maker, the amount of experience points required to level up for each actor can be adjusted, usually via a formula adjustment which is different for each edition of RPG Maker, or manually adjusted for each level using scripting or plugins. The increase in stats for each ability and the skills learned for each level can be changed in the database as well. By default, the level limit for RPG Maker games is 99, but it can be changed using plugins or scripts. In RPG Maker 2000, the limit is only 50.
It is possible to set the amount of experience each enemy type gives in the database. There is also an Event command that increases the amount of experience of members in the party, which is useful as a quest reward.