How does it work exactly? Gameplay wise...?
Well, its confusing at first. You create a char in the typical fallout 2 fashion and you are thrown into the wasteland with almost nothing and no guide or quests telling you what to do. (much like Dayz)
You lvlup and get gear the usual way, do quests, kill random encounters, buy gear or loot it from players. You can basicaly do whatever you want. Kill, trade, rob (you can use steal on players), get a car, join a gang, get a gang hideout, do gang wars etc. There are typical cities you might recognize from the game where the players go to trade/pvp (NCR, Necropolis, Vault city, New reno etc.)