Spleef

Everyone gets one Efficiency V shovel and nothing else. The floor is a single block type, picked fresh every match, and underneath it is a pit of water or lava. Dig through the floor where someone is standing, watch the holes other people are digging for you, and stay on whatever is left. Nothing here deals damage: hitting another player shoves them, so the whole fight is about footing. When the clock runs out the floor starts collapsing inward from the rim, and it does not stop until there is none of it left.