Find Hardcore mode Minecraft servers here . This mode is where you have 1 life. When you die, you will get temporary banned from the server. The duration of the deathban is set by the individual servers. Normally between 1 hours and a few days or until every player is dead on the current map. It will then restart with a new or the same map.
This type of gameplay is not for the weak - get ready to defend yourself and do not wait for the others to shot the first arrow :)