Effect

Status effects are various conditions, which can be either helpful or harmful, that affect an entity. They can be inflicted in various ways throughout the game, including consuming potions and some food items, being in the range of beacons and conduits, and being attacked by or close to certain mobs.

The command allows players to inflict effects upon themselves and other players and entities.

Behavior
Any entities inflicted by a status effect will be affected in various ways for an amount of time. During the effect, swirly particles emanate from the position of the inflicted entity. Players can open their inventory to see any current status effects afflicted upon them, as well as its level and duration. For most effects, higher levels increase the strength of the effect.

Internally, and in the command and potion Amplifier NBT tags, the game stores an "amplifier" value, which is one less than the displayed level. For example, Strength II has an amplifier of 1.

Due to the way this amplifier is stored in NBT, amplifiers of 128 to 255 (levels 129 to 256) in NBT tags (e.g. on potions) are treated as if they were −128 to −1 (levels −127 to 0) respectively. The command initially applies such amplifiers in their positive-valued sense but this is later converted to the negative-valued interpretation, leading to inconsistent results.

Any number of different status effects, including opposing effects such as Strength and Weakness, can be simultaneously active on a player. However, it is not possible to apply the same effect multiple times, even if they are of different levels (e.g. Strength and Strength II). When applying an effect already active on the player, higher levels overwrite lower levels, and higher durations overwrite lower durations of the same level.

Note that even with commands, effects cannot be made to last forever. If an effect is set to an excessively large amount of time, such as 182 hours (655,200 seconds), it will display as "**:**", but will still continue ticking down and eventually expire.

All status effects can be removed by drinking milk, dying, being saved from death by a totem of undying, or traveling through the return portal in the End. Singleplayer users with cheats enabled and operators in multiplayer servers can use or  to achieve the same goal.

Trivia

 * If the player puts Blindness and Night Vision together, the screen will turn black and only the sun and moon will be visible (except in rainstorms or thunderstorms).
 * The maximum health the player can achieve using Health Boost and Absorption is 2068 (1034 hearts).
 * If the player gets max health using the method above, and adds Regeneration with the level of 255, while healing to 1034 hearts, their view will jolt, even in Creative mode, as if they are taking damage.
 * If the player has at least Resistance 5, then they are practically invincible (apart from the command and the void).
 * If the player has Regeneration 7 or higher, the void cannot kill them.
 * The Wither effect is the only negative effect that can negatively affect both living and undead mobs.
 * The Jump Boost status effect does not make slimes, magma cubes or guardians jump higher.
 * Speed allows slimes to jump farther. High levels of speed can make slimes bounce out of view with just one jump.
 * The Levitation status effect will normally rise the player into the air. However, if they go into water, they will just flow along with the water, while not floating.
 * When having multiple status effects, the status effects' timer's seconds will always be reduced by 1 each simultaneously regardless when the player takes another potion. This is because they use the same "seconds counter" that "ticks" every 20 game ticks to save memory. For example, if the player drinks one potion and another potion (which is different, so that it doesn't reset the timer) 5.5 (or any non-integer amounts) seconds later, both status effects' timers will subtract 1 second from both of them simultaneously.
 * The player can walk/run while having the Levitation effect, especially on level 254.
 * Although the Wither effect is given to the player by being hit by wither skeletons or the wither, the icon shows a normal skeleton head instead of a wither skeleton head.
 * Using will make the player fly in Survival and not jump, when the effect is over in Survival when in midair, hitting the ground will cause them to shoot into the air, then the player will most likely die.
 * When a creeper has a status effect and explodes, it leaves a lingering potion cloud of the effect(s) that it had before it died.
 * The Conduit Power status icon reuses the old heart of the sea texture.
 * In Windows 10 Edition version 1.1.5, if the player has a high level of the Regeneration effect, then they go to lava, then it would be fast. When in the Resistance effect, the Absorption effect hearts appear, as if they have the Absorption effect. When having the Regeneration effect, the Resistance effect, and the Absorption effect at the level 256, then the player would not die, even with the command and the void.