This is a server mod (clients don't need anything special) that does Hide and Seek and Zombie modes.

RULES :

INSTA ZOMBIE mode (instagib team): If you are in team zomb (zombie), you must kill everyone in team huma (humans) so that they become zombies. Humans have 100 + 70 * number_of_zombies maximum life and their life regenerates at 10 points per second. Humans can kill zombies in one shot. Teamkills are impossible.

HIDE AND SEEK mode (efficiency team): If you are in team hide, you must hide from the seekers. If you are in team seek, you must kill hiders and they will also become seekers. Hiders cannot kill seekers. Teamkills are impossible.

HIDE AND SEEK ZOMBIE mode (efficiency team and type "#zombie 1"): If you are in team seek, you must find and kill people in team hide. They then become seekers as well. Hiders' life regenerates and they can kill seekers but seekers are more resistant. Teamkills are impossible.

You are free to use it, tweak it, report bugs, make suggestions,...
Please distribute source code if you make modifications.

UPDATE: a slightly improved version is now linked here.

If you are running this server, please leave a comment explaining how to access it (address and port).