This is for Counter Strike players who play on Zombie Horde and/or Zombie Swarm servers.
If you're playing as a T (zombie)
Always run towards CTs. Try to trap CTs into a corner so they'll have no place to go.
Try to sneak up to CTs and slash their heads. This is pretty much the most effective way to kill CTs. You don't risk yourself getting hit by bullets this way.
Try to scare the CTs. This will shock CTs which might result in CTs freezing there on the spot unable to do anything. They also might go full auto with their weapons which wastes their bullets and keeps you from getting hit by bullets.
I think the best way to play in Zombie Horde/Swarm servers is to become a zombie.
If you're playing as a CT (zombie killers):
Buy weapons that have a lot of bullets (e.g. Machine Gun) or are very powerful (e.g. AK-47). Buying weapons with lots of bullets will supply you with a lot of ammo so you don't have to reload a lot and worry about running out of bullets. Buying powerful weapons will help you kill zombies faster.
Always back away from zombies when attacking. This prevents you from being attacked by zombies because you're constantly shooting (pushing the zombies away) and keeping your distance from zombies. You must know the current map very well or else you might back into a corner and get killed.
Look behind every 3 seconds while you're running. You never know when a zombie might sneak up on you and kill you. Also, check every corner and hiding place. A zombie might be waiting to jump out at you.
Try to stay cool and calm. If a zombie jumps out at you, you might be so shocked that you'll become immobilized. This is the time when you're most vulnerable to attacks.
Tips for Zombie Killers and Zombies:
Learn to bunnyhop. It's way faster than running which gives you a great advantage to chase down targets or to run away.
Always stick together with your teammates. your team will be more powerful that way making it easier to kill enemies.
Always perform evasive action to dodge enemy attacks.
These tips may also work in Zombie Infection servers. I can't be sure because I've never played on Zombie Infection servers.
