Alternate character, often referred to in slang as alt or alt char, is a term primarily used in MUDs and MMORPGs.

An alternate character is a character that a player creates in addition to his or her "primary" player character. Usually, the player makes this connection between either him/herself or the primary character clear - sometimes this is required by server policy, or this could be enforced via direct technological means - but sometimes they try to keep this connection secret.

Typically, alternate characters are used less frequently than the "primary" characters, but sometimes players may use them just as often. They should be distinguished from completely unused (dormant) characters, which may even get deleted for lack of activity.

Alternate characters are primarily used for role-playing purposes. People may use different kinds of characters for different kinds of roleplaying. Many people use this to experience the different abilities of different player races, or character classes. Also, one of the frequent (yet still somewhat controversial) use is to play characters of opposite gender. Also, frequently, people use alternate characters to "re-live" the game experience; high-lever characters may end up running low of things to do, but deleting the character and starting completely over is often undesirable. Often, people create another character to see what new features have been added since they last were on low level.

The games typically allow alternate characters as long as they don't consume game resources excessively and are not used for cheating. Often, the servers have specific rules about the use of alternate characters. Most typical rules include the following:

1. The player is limited to certain number of characters.
2. Only one character may be logged in at the time.
3. Any player's characters are not allowed to interact among themselves in any way. Often this only includes interaction which has a tangible benefit (such as giving equipment or money to another character), but some even restrict in-character dialogue.
4. Alternate characters must not be used to spy on another guild or faction.

The term multi is a similar idea in that it is heard in a wider variety of genres, such as strategy games where players control something other than a character. Multi connotes the use of an alternate character (empire, army, or whatever) to the advantage of the primary character, which many games consider cheating.