Left 4 Dead 2 also features a Realism mode, which can be enabled at any difficulty for either Campaign or Versus. This mode removes some of the video-game aspects from the gameplay: Survivors cannot see each other's silhouettes, and dead teammates can only be revived with defibrillators and will not respawn later in the level.[16] Weapons and other items will only glow when the player is within a few feet, forcing the players to search the levels more thoroughly. Headshots to enemies deal more damage, whereas limb or body shots require more shots.[17] In addition, the Witch enemy can kill any Survivor she would have normally incapacitated (on difficulties other than Easy). Designed to force players to work closely together and rely on voice communication, Valve created Realism mode to give players a way "to be challenged as a team" without having to increase the difficulty level of the game.[16]