Players 9, 10, 11, and 12 are extraneous neutral players that can be used for many capacities but have many limiting attributes (Player 12 is listed as 'Neutral' in Scmdraft). Players 9 though 12 cannot own triggers, and hence cannot run AI scripts, disabling the ability to set alliance or vision statuses. If provoked player 9-11 units will follow the assailant but not attack it- this is because they do not have vision (and cannot be given it by any means), not even for their own units which makes them unable to attack. You can read Player 9-12 death counters but you cannot set them by actions (adding to their death counters must be done manually by killing their units) effectively eliminating use of their deaths as a dynamic variable.

While players 9-11 act as hostile computers without vision, player 12 is neutral. When any player leaves the game their units are automatically given to player 12. Similarly, all dark swarms and disruption webs are cast automatically owned by Player 12, no matter the player that cast it; this is why it is impossible to know which player cast them unless only one player could have (IE only one player has the ability to cast it, or only one player has a defiler/corsair within range to cast it). Abandoned addons are automatically given to player 12 and resources are owned by player 12.

Perhaps the most intriguing aspect of player 12 is that players retain alliance statuses with units given to player 12. If player 1 is unallied with player 2 and a player 2 unit is given to player 12 unit, player 1 will still be unallied with that unit, despite his alliance status with player 12. If player 1 then allies player 2, player 1 will then be allied with all player 12 units that were given from player 2. Setting alliance status with player 12 only effects the player's alliance status with preplaced player 12 units and the color of the selection ring (yellow vs red) around player 12 units.

Players 9-12 can not have units created owned by them, but can be given units (even immediately after creation by different player) and can have preplaced units. Units given to player 12 also retain their colors (however, this is not reflected on the minimap). Players 9-12 do not need start locations, cannot be set to human open slots, cannot have player color set and cannot be seen in the game lobby.