/effect Command
Applies or removes status effects on players and other entities. 'give' adds an effect for a specified duration (or infinitely); 'clear' removes a specific effect or all effects from the target.
Syntax
effect give <targets> <effect> [<seconds>|infinite] [<amplifier>] [<hideParticles>] | effect clear [<targets>] [<effect>]Permission: OP level 2Edition: Both
Examples
/effect give @p minecraft:speed 60 2/effect give @a minecraft:night_vision infinite 0 true/effect clear @s minecraft:poison/effect clear @aNotes
Duration range is 0–1,000,000 seconds; amplifier range is 0–255 (displayed in-game as level+1, so amplifier 0 = Level I). The 'infinite' keyword (Java only) applies the effect permanently until cleared. hideParticles true suppresses the ambient particle cloud. If a stronger effect of the same type is already active with a longer duration, the new application is queued but hidden.