Valve have confirmed that Realism Versus has become a permanent game mode in Left 4 Dead 2 after a poll they held demanded it, with a result of 68% in favour of the mode sticking. Previously, the mode was one of the weekly game “mutations”, which introduce different game modes. Valve will hold a poll every month for players to pick their favourite mutation. Realism Versus removes the glow around survivors and items, makes zombies stronger and gives witches the power to kill you instantly.

The next mutation will be Follow the Liter, where survivors have to follow a trail of gas cans in order to scavenge them, with each can spawning one at a time.  However, the infected know exactly where the cans are too.