Left 4 Dead Health Packs

Health packs in Left 4 Dead are one of the most powerful and mis-used items in the game. It is very important to understand how to maximize their potential. Health packs serve two purposes:

• Healing a survivor. This may seem obvious, but health packs in L4D only restore 80 percent of a survivor's available health. If you are at 50%, a health pack will give you 40 hit points to heal you to 90% (80% * 50% = 40%; 40% + 50% = 90%). If you are at 30%, a health pack will give you 56 hit points to restore you to 86% (80% * 70% = 56%; 56% + 30% = 86%). The lower your health, the more benefit you will get from a health pack. This also means you can never heal to more than 99 percent. If you're using a health pack on somebody (you or a teammate) isn't red, you are wasting health restoration points.
• Resetting the incap counter. Once a survivor has been incapped and helped back up twice, they start slowly bleeding out. Their screen turns black and white, and they will die on the next incap. The ONLY way to prevent death from three incaps is by taking a health pack. It restores their health and resets the incap counter.

That said, here are some good and bad times to use a health pack.

Bad times:

• Early in a level where you got brutalized by the horde and are at 40-99% health. You aren't moving that slow at this point, you don't need to waste the health pack. Save it for a better time.
• Right after you've taken pain pills. Pain pills temporarily restore all you health. Taking a health pack at this point wastes the pills.
• When your entire team is a similar health/damage level. If everybody on your team is at 20-30% health and moving kind of slow, taking a health pack by yourself will make you too fast. You'll tend to run ahead and get separated.
• Right before trying to mess with a witch. Even the best players in our clan can not take out the witch successfully 100% of the time. The witch's primary attack is an auto-incap and immediately zeros out the survivor's health. As long as the rest of the team is close enough to take the witch out pretty quickly after the intial attack, it often makes sense to send the weakest player in to piss her off.
  
• In Campaign mode on Expert: You should NEVER take a health pack until you've been incapped twice and your screen is black and white. Health packs NEVER appear on the level, only in safe rooms. They should only be used to reset incap counters or to heal before picking up a new pack.

Good times:

• When a survivor has been incapped twice and their screen is black and white. This should always be a priority. Having a dead survivor is almost always the worse of the alternatives. Reset their incap counter so that you have an extra gun, and an extra survivor to revive you when you get incapped.
• To pick up a new health pack. Never leave health packs unused. If you see a health pack on the level, and everybody is already holding a health pack, the player with the lowest health should heal, and then pick up the new health pack. Often times there will be health packs at the site of a big battle. It is usually better to use the health pack(s) AFTER the battle, than before.
• Once everybody is inside the safe room. On Versus, you get points for much health you have. Everybody should heal before closing the door to maximize your score. Don't stand too close to the door while survivors are healing though, because the Infected can still get you until the door closes.
• When you are the weakest link and speed matters. If you are the only survivor who has significant damage to the point where you are slowing down the party, and where the team would do well to progress quickly, then you should heal so that you can keep up. This typically means you are below 30 percent health, and you are in a wide open area. Because of how the horde spawn spots are set up, there are not too many places in L4D where speed is more important than saving health packs. So use them wisely.

Remember that the way we play L4D in Versus, both teams can hear each other the whole time. You basically have to announce that you're using a health pack so that your team mates don't run off ahead. Once you've announced it, you've basically advertised to the Infected that your team has spent one of its four precious health packs (and are now weaker for it), and that your team will be sitting in one spot for a while waiting for you to heal (and be vulnerable to easy Infected attacks).