structural:expansion, information:classification
Basic rules

Players (two or more) decide who is going to be "it", often using a counting-out game such as eeny, meeny, miny, moe or rock paper scissors. The player selected to be "it" then chases the others, attempting to "tag" one of them (by touching them with a hand) as the others try to avoid being tagged. A tag makes the tagged player "it". In some variations, the previous "it" is no longer "it" and the game can continue indefinitely, while in others, both players remain "it" and the game ends when all players have become "it". This variation of the game is sometimes called "Family tip".

Many variants modify the rules for team play or place restrictions on tagged players' behavior. A simple variation makes tag an elimination game, so that tagged players drop out of play. Some variants have a rule preventing a player from tagging the person who has just tagged them (known as "no tag-backs", "no catch-backs", "no returns", "can't tag your master" or "can't get the butcher back").