Left 4 Dead 2 is now available, and Valve improved on the original in a number of ways. Melee weapons, increased difficulty, excellent new scenarios (wait until you fight zombies in the middle of a storm) and more await. And then there's Realism mode, which is a whole new ballgame. If you have trouble making it through this, we've got some advice that'll help. Follow it, or fall prey to the zombie apocalypse.

Stay together

We cannot emphasize this enough. This is a group-oriented game. The best way to survive is to stay with your teammates. All it takes is one encounter with a special Infected, like the Charger or the Smoker, and you could be done for. By keeping your teammates close, they can rush to your aid and, on occasion, provide you with health or pills to keep you alive. (You can help them out, too.) There is no one-man army.

Use melee weapons sparingly

Are the new melee weapons awesome? Absolutely. Conking zombie heads with a frying pan is lots of fun, and we can't tell you how many runs we've made through groups with a chainsaw. However, you should keep your finger on the weapon button, just in case. While melee weapons are effective, they won't do a lick of good against the special Infected. You cannot defeat a Tank with a guitar, no matter how good a player you think you are. It never hurts to have a good stand-by, whether it's a machine gun or an automatic shotgun.

Don't rush for the escape unless everyone's with you

Let's say you make it to the final stage of a campaign, and a rescue boat or chopper is a few steps away. Is this the right time to go for it and get out of danger? Not necessarily. It's when rescue arrives that the zombie onslaught is at its most frantic, with Boomers, Tanks and other monstrosities attacking like crazy. Rather than making a run for it and risking the loss of teammates, don't be afraid to make one last stand. If you've got the ammunition and the health, you can slowly make your way to safety with everyone in tow. Remember, the group that stays together, slays together.

Reload often

No matter what kind of guns you carry (twin pistols, assault rifle, grenade launcher), you'll always want to keep them full. If you're in a quiet spot with no zombies around, go ahead and reload your weapon. It'll make all the difference when you've got the horde coming after you, or larger enemies like the Charger or Tank heading your way.

Use health wisely

In each safe room, you'll find a number of health packs at your disposal. After making sure you're in good health, go ahead and grab an extra to carry along. This'll come in handy for not only healing yourself, but taking care of a teammate should they fall victim to a sudden attack. For that matter, pain pills can also make a world of difference, and if you have the space for it, grabbing a defibrillator wouldn't hurt; use this to revive fallen teammates.

Listen to the audio for clues

The music and sound effects in Left 4 Dead 2 don't just provide excellent background ambience. They also serve a purpose. Throughout the game, your peers will constantly yell out warnings about special Infected. "Boomer!" "A Hunter's nearby!" Keep an ear out for these, and then follow their lead. They might just know where they're hiding. For that matter, listen for specific zombie growls, such as the belching Boomer or the screaming Hunter. Music cues also pop up from time to time. If there's a sudden change to the soundtrack, prepare for the worst.

Don't ask for trouble

Even if you're carrying a bile bomb and a grenade launcher, that doesn't mean you're fully prepared. There are times when you can avoid trouble, such as leaving car alarms alone or shining a light where it doesn't belong. Unless you live for the thrill of the hunt and know for certain you can survive a wave of zombies, avoid causing trouble at all costs. The name of the game here is survival, not stupidity.

Beware of the wandering Witch

In the original Left 4 Dead, the Witch was easy to get around. She just sat in place crying her eyes out, and as long as you left her alone (and didn't do something stupid, like shoot her), you were good to go. However, in the sequel, you don't have it that easy. The Witch now walks around, making it more difficult to avoid her; she'll hear and smell players if they get within range. If you hear a witch, play it safe and keep your eyes open. Otherwise, you're in for a hell of a fight.