Requirements:
A strong executor
55 Robux
An autoclicker
To lag the server, make sure your autoclicker is on the fastest setting. That could be 0 clicks per second. Then just copy and paste the script in your executor one time and once attached, have your auto clicker on for a few seconds pressing execute while your grenade is in your hand. Stop the autoclicker whenever you are ready. The closer people are to you the more lag.
To crash the server, do the same as above but paste the code a few times in your executor with the autoclicker. I would say at least 150 lines of pasted code.
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