Ok. say ur on a server where tnt is allowed. and this guy really ticks you off. say he also has a smooth stone or wooden floor of his house. heres a way to get revenge for ticking you off. wait till hes not around (or off the server) then go into his house and dig 2 blocks down wherever. then place redstone dust on the spot where you're standing.
now for the fun part. dig a spot underground where the tnt will react with the redstone. place the tnt there. now replace the spot on the floor where you dug with the same type of block. now place a pressure plate there. make sure the pressure plate closely resembles the floor. and now youre done. just wait for him to step on the pressure plate and-KABLAM! he dies and his house is trashed. win-win!

hope u like this!