A fun capture the flag meets bridges gamemode.
The map(s) would be an underground series of intertwining mining tunnels that are mirrored on each side to provide no advantage to any team.
Each player would get a stone shovel, pickaxe, and sword to start out. Randomly spawning in random locations on the map, would be sticks of dynamite, which players could pick up, and replacing their sword. Then players could run to the opponents side, and throw the dynamite at the custom entity support beams that are keeping the opponents base from caving in. If all 4 support beams loose all their hp (the closer the dynamite stick is to the beam, the more damage it does) then that team is out, teams have infinite respawns but drop all gathered items when killed, such as blocks, dynamite, opponents items.
But as soon as your supports are knocked out, your base caves in, and you are instantly out.
The dynamite, when thrown, deals damage to any support beam but your own, nearby players (including yourself) and destroys any nearby player placed blocks.
Thanks for ready all this XD im so sorry this is so long. If you dont feel this idea is any good, i understand, but if this idea actually has some potential, please just keep it around and stuff it away somewhere so if yall are brainstorming what to do, it might come up