I know that's hard to do and it will probably impossible, but i'd like to have a open world and mmo mode:
It's a all vs all, you start normally and you spawn in the "city". The city is undestroyable and safe-zone.
In the city you can find buildings or npc:
Market: when you go near to it there will be a message on the board with the codes you can write for buying things:
example:
/blocks 50 (1$ per block)
/Gun 1-2-3 (150$ to change your weapon)
/Ammo = Refill (1$ per bullet)
/nade = 50$ per granade
Doctor: pay 1$ per hp. There is no a tent ( or maybe It's on a tower in the map, so that it is considered a "Quest" )
Military base: here you can make squads using /squad namesquad and paying 100$. player in a squad can't kill player in the same squad.
Mage- It should have some of the skills of the "iRPG" game, like lvl 1-2-3 (20-50-100$) lvl 4 (200) lvl 5 (400)
Working base- gain much $ completing quests like " get a 10 killstreak ", "destroy/build 50 blocks", etc
You can gain $ killing enemies too ( 5$ for kill, 10$ for headshot )
If you kill the same person 2 times in a row it won't give you money.
If you die like 3 times without killing you will lost all your money.
more rules
when you go out from the safe zone you can't be killed for 5 seconds, and you can't kill anyone. ( prevent camper- killing near to the spawn)
You can't get too much powers from the mage (prevent overpowered players)
When you get killed you lost all powers you bought.
The game ends when someone gets "x" kills
If you die you will lose half your money. If someone kills you he gain the 5$ for kill plus 1/10 of what you losts (minimum 1$)
Other codes:
/m = see your current money
/m nameplayer = see current money of the player
What do you think? suggestions?