this is a thing I used to do on creative servers
I will get TnT or command blocks and input the @p /kill command I need 5
rules
#1. there are command blocks with the /kill command and 4 with /pay 25
#2. for every round there the players attend it doubles to 50 then 100 then 1000 then 10000 if they win the fourth round
#3. every round they participate there will be 2 then 3 then 4
#4. if they win all four rounds they get put into a bonus round where if they live they get to keep everything
#5. if they die at anytime or they get the block with the /kill they lose everything
#6. if they are suspected of cheating they will start over with a penalty
#7. if they win all 5 rounds they get the option to enter more rounds with 10 blocks when that is finished they get to choose their prize the cash prize does not count if they go down this path
for example if they choose to enter the round all cash prizes don't matter