Hellrising is a game where you play as a vampire/human/zombie in a quarantined city. Its a text based game that runs on ap system. adding strategy into the mix to plan out your moves or you could be stuck outside or worse. It has npc's as well as unique drops making the game both pvp or pve (though its more pvp oriented) There are many items you can find in the game, or craft out of items you find if you have the crafting skill. I would suggest joining a group and finding a walkie talkie in a police or fire station as it allows one to talk to the whole game/group allowing people to work together.
This is just basic description of the game obviously there is much more to the game than this but this is the bsics.
Here is some other info you can use
Game link: http://www.hellrising.com/index.php
Guide: http://slimebeast.com/forum/hell-rising/tyr's-newbie-guide/
Game map: http://img2.wikia.nocookie.net/__cb20141028012048/hellrising/images/0/00/Serling.png
