Our cool features:
1. Voice comm and sound is 3D-positioned and affected by range. That is, your voice will appear to others to be originating from your character, and its volume will be affected by how near you are to them (I think the range is 80 meters or so? Someone correct me...). Everyone within that range will be able to hear you and determine what direction the sound is coming from if they are using headphones. It is as if you were actually speaking within the game world.
Also, when you use direct voice, your character's mouth moves along with the words you are saying. It's actually pretty freaking cool. People really need to take better advantage of it.
2. Permanent death' (article on the BBC:
http://www.bbc.com/news/technology-18280173)
Word got round and the mod quickly became a huge hit as those early testers shared their experiences. Within weeks of it being released, it had 4,000 players on 90 servers. Numbers have continued to climb since then and now the game has almost 150,000 regular players who control 1.8 million characters.
Mr Hall said he had deliberately made it hard to survive, so players felt threatened from the moment they started. The threats facing them go beyond just being killed and eaten by zombies. The realism of Arma II means they must scavenge food and water to stay alive, and must bandage themselves if injured or they risk bleeding to death.
A recent update introduced diseases that can only be cured with hard-to-find antibiotics and which can be spread from player to player. In addition, some players of Day Z have become bandits who prey on other people.
Statistics on the Day Z mod website show that average survival time is 28 minutes.
To these permanent threats, Mr Hall added mechanics that helped players connect with their character. Instead of characters being created afresh every time a player joins a Day Z server, they take their character and the gear they have gathered with them.
"I believe the persistent world combined with permanent death switches something over in the player's mind which causes them to play in a different way than they usually do," Mr Hall told the BBC. "It sort of hot-wires on existing emotions and instinctive processes, which I think is why players are having some really emotionally intense and vivid experiences in the game."
3. Hunting and Survival - Eating and drinking is a core part of gameplay, you can tell if you need something by a very subtle GUI which doesn't effect the atmosphere, and if you don't fulfil those needs. You'll die. Wandering animals can killed and gutted (with the right tools) to gain access to their meat which can be eaten so you live longer but also to gain blood. For once these animals actually have a use.