Here are some tips specific to Capture the Flag:

• Know where the flag is. Play each map in single player and find out where the flag is, so when you’re playing for real, you can get a headstart.
• Learn to use the Translocator. It can help you move around the map very fast, and reach normally out-of-reach places. It can also be used to score a kill.
• Don’t use the Translocator once you have the flag, as you’ll automatically drop it when attempting to translocate.
• Help the person carrying the flag by getting in the way of fire and trying to take the chasers away. Do whatever you can to give your teammate a chance at getting the flag back to your base safely.
• If you have the enemy flag, but the enemy also has your flag, hide. Don’t go out and fight, as you can potentially lose the flag. Don’t hide out at the capture point, either, but a safe spot away, somewhere secluded. As soon as you learn that your flag has been returned, hightail it to the capture point.
• Use the Bio Rifle to litter the floor around your flag with goo, causing damage, and possibly death, to anyone attempting to get your flag.
• If you have the flag and the Bio Rifle, run backwards while firing the Bio Rifle at any people chasing you.