CSB Random Fun Events rolls a dice at every round start. On a hit it picks one of several events and applies it to every player as a clean apply/revert pair: Low Gravity, Giants (model scale plus bonus HP), Hyper Speed, Knives Only, or a Rocket Slap Party that periodically launches everyone into the air. The event is announced in chat and on the HUD, re-applied to anyone who spawns while it is running, and fully reverted when the round ends.
csb_events_chance.fakemeta and fun modules in modules.ini.csb_random_events.sma, copy it to addons/amxmodx/plugins/ and add it to plugins.ini.