Fog of war
Fog of war hides the actions or status the players who are beyond a certain range.
Strategy or combat videogames often employ this pattern (finer variations such as shroud vs. fog can be found in these games). The pattern is more meaningful for game areas where the other players might physically be out of range of visibility. Those could be large areas, or areas that are separated, such as rooms or floors in a building. As the distance of players from other players or from points of interest increases, the fog of war obscures information. This way, proximity or other patterns related to physical space can be combined with the fog of war in order to create a dynamic information awareness pattern.
Fog of war can be combined with the possession of a digital object which enhances range or temporarily lifts the fog. The same effect could be created by allowing players with different abilities to cooperate in order to jointly lift the fog of war.
The presence of a fog impels players to move in the game area and it is an incentive for exploration. In large physical spaces players might have to plan their areas of focus.