Screenwatching is a slang term. The term refers to the act of looking at another player's "screen" during a split-screen multiplayer game. A variety of synonymous phrases exist, including screen jumping, screen looking, screen peeking, screen checking, screen cheating, screen hopping, peeking, and screening.
In a split-screen game, the viewing device being used (be it a television set, a computer monitor, or something else) is divided into separate regions, allowing multiplayer players to use a single screen. Each of these regions functions as an individual screen (and is referred to as such), such that despite the usage of a single viewing device, each player has their own viewpoint and heads-up display.
Unfortunately, however, such a setup allows a player to glance at the screens of others. By doing so, a player can instantly discern the whereabouts and armaments of other players. This gives the observer -- the screenwatcher -- a tactical advantage in both offensive and defensive situations; in the former, the screenwatcher can more easily intercept their target, and in the latter, they can more easily avoid their target. The screenwatcher can even tell if they are being aimed at, and can thus evade would-be snipers and assassins. By the trick's very nature, however, it may be turned against the screenwatcher -- if the other players decide to screen cheat in retaliation, then the trick could be considered to be an additional layer of strategy.
In Halo: Combat Evolved, Halo 2 and Halo 3, screenwatching is usually unavoidable to an extent, particularly when the players are playing on a small monitor. Despite its inevitability, screenwatching is looked down upon as a "newb" tactic.
- Screenwatching is often considered cheating. Obviously, Bungie cannot ban people for it; it is cheating in a more informal sense.
- An easy way to avoid screenwatching, or at least lessen the impact of it, is to create a System Link with multiple Xbox consoles on multiple monitors, so that players each have their own screen, or at least have fewer opponents on one screen. In a team game, the game can be set up so that teammates share screens; screenwatching in such a case will provide only a minor advantage.