- Healthpacks: They heal 80% of your injuries and reset your incap count, rather than healing an exact amount of health.
- "International" version weapons: If you come across a weapon you haven't seen before, it's because you're playing with someone that has the German version of the game.
- Hunter pounce damage: Not determined by how high above the survivors you reach, but rather how far the spot you jump from is to where you land.
- Boomer vomit has a sort of cooldown effect. If a boomer explodes on someone that has been vomited on, the effects won't stack and will wear off when the vomit was timed to normally.
- Teamwork is just as important for the infected team as it is for the survivors. If you don't attack with your teammates, even mediocre survivors will make all your attacks worthless.
- If you are a Survivor, NEVER, EVER, EVER LEAVE THE GROUP. If you dash ahead, you'll be a prime target for the Infected, no matter how good you (think you) are, or how many guns you are carrying.
- When killing a witch with a shotgun and your on Normal or lower, go for the back. The back's the largest area of the witch and gives you time to fire another round if the first one wasn't enough.
- Set tanks on fire, it'll slow them down unless you're in Campaign on the original game.
- This goes without saying: always have a strategy planned out in your head beforehand, and work out two others as backups. More often than not, Plan A will fall through, while Plan B might just save your life.
- Even though rooms and the ambiance are dark, don't keep your flashlight on all the time. The Infected may be bloodthirsty, but they aren't stupid: shine a light on a zombie, it will sense you there in a quicker time than usual
Useful Notes / Left 4 Dead
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