A status effect is a temporary condition applied to a character that changes what they can do or how they take damage, such as poison, stun, slow, or burn. Effects have a duration and often a visible icon and timer.
Status effects come in two broad families. Damage over time effects, such as poison, bleed, and burn, reduce health in ticks while the target keeps fighting. Control effects, such as stun, freeze, root, and silence, restrict action itself by stopping movement, blocking abilities, or removing a turn. A third smaller family covers stat changes, where attack, defence, or speed is raised or lowered for a set time.
How effects interact decides their depth. Some stack, so a second application adds damage or refreshes the timer. Some overwrite, so only the strongest version counts. Many games let players remove negative effects with cleanse abilities, specific items, or simply waiting, and bosses are often partly or fully immune to control effects so a fight cannot be locked down forever.
In Pokemon battles the parallel concept is the status condition, covering set conditions such as burn, paralysis, and sleep with their own persistence rules. The vocabulary differs by series, but the core idea is identical across games: a named, timed state layered on top of normal health and damage.
In play"The boss was not hard until the poison status effect started ticking during the final phase."