Left 4 Dead 2 mutation "Realism Versus" has become a permanent fixture for the game.
The variant removes glows around survivors and items, makes zombies tougher and witches instantly lethal. A considerable 68 per cent of voters said Realism Versus should stick around, forever.
The next mutation will be Follow the Liter. The idea here is for survivors to follow and scavenge a trail of gas cans, spawned one at a time. Survivors will have an easy route to follow, as will the Infected.
Mutations are game mode variants being trialled on a week-by-week basis. Valve will hold a poll every month for you to pick your favourite.
The mutations will cover different game modes and be available across all campaigns.
The Left 4 Dead 2 blog can tell you more.