Acronym for 'Jump In
Game', when a
player repeatedly uses the jump button or key to constantly jump for no reason whatsoever.
Once upon a time this was commonly referred to as 'bunny hopping' which was used as an exploit in Counter Strike. These days, this behaviour is most prevalent in online multiplayer games such as WoW where players will be seen 'jigging' around Ironforge just because they can.
Some gamers prefer solo-jigging. Solo-jigging can be enjoyed in single
player games such as Oblivion.