What about car bombs? Or, at least, vehicle bombs? My idea is like this, though so far limited...
What you would need would be some sort of weapon that would allow a player to hide a fairly powerful bomb inside an unlocked vehicle. This bomb would then explode when a player got inside for any reason, destryoing the player and the vehicle (save the Leviathon. That would probably take a bit more then one bomb). This would probably be the primary fire.
Secondary fire would allow the bomb to be attached to the outside of the vehicle, and detonated by the driver from within. The explosion would need to be fairly powerful to be worth anyone's while, but there would be endless possibilities!
I think the needler would be great for adapting to this but I want it to be capable of its current uses. Armor penetrating needles with high explosive, timed tips perfect for blasting that Levi to kingdom come, after you have ran away.
Jingle, jingle, boom. Oops, you're dead.
That sucks cause I wanted to play....
But let the show go on!
one idea that was mentioned was that you could place team enabled Firemines under a vehicle.
these would not be tripped by the vehicle because the two would be on the same team , but as soon as the enemy hopped in , the mine would go off from underneath.
