Experience point

An experience point (often abbreviated as exp or XP) is a unit of measurement used in some tabletop role-playing games (RPGs) and role-playing video games to quantify a player character's life experience and progression through the game. Experience points are generally awarded for the completion of objectives, overcoming obstacles and opponents, and successful role-playing.

In many RPGs, characters start as fairly weak and untrained. When a sufficient amount of experience is obtained, the character "levels up", achieving the next stage of character development. Such an event usually increases the character's statistics, such as maximum health, magic and strength, and may permit the character to acquire new abilities or improve existing ones. Levelling up may also give the character access to more challenging areas or items.

In some role-playing games, particularly those derived from Dungeons & Dragons, experience points are used to improve characters in discrete experience levels; in other games, such as GURPS and the World of Darkness games, experience points are spent on specific abilities or attributes chosen by the player.

In most games, as the difficulty of the challenge increases, the experience rewarded for overcoming it also increases. As players gain more experience points, the amount of experience needed to gain abilities typically increases. Alternatively, some games keep the number of experience points per level constant but progressively lower the experience gained for the same tasks as the character's level increases. Thus, as the player character strengthens from gaining experience, they are encouraged to accept new tasks that are commensurate with their improved abilities in order to advance.

The term "experience point" was introduced by Gary Gygax and Dave Arneson in the creation of Dungeons & Dragons. Arneson introduced a level-up system while playing a modification of Chainmail, for which Gygax was a co-author. Dungeons & Dragons needed an abbreviation for "experience point", but EP was already in use for "electrum pieces", part of the currency system. One of TSR's first hires, Lawrence Schick, suggested the abbreviation to XP, to help Gygax complete the game manuals before release.

Some games use hybrid advancement systems that combine elements from more than one of the following types.

In many role-playing games, such as games derived from Dungeons & Dragons (D&D), an accumulation of a sufficient number of experience points (XP) increases a character's "level", a number that represents a character's overall skill and experience. To "level" or "level up" means to gain enough XP to reach the next level. By gaining a level, a character's abilities or stats increase, making the character stronger and able to accomplish more difficult tasks, such as safely battling stronger enemies, gaining access to more powerful spells or combat techniques, or resolving more difficult social challenges.

Typically, levels are associated with a character class, and many systems allow combinations of classes, allowing a player to customize how their character develops.