Combat status affects abilities, runes, items and buffs. A champion is in-combat upon damaging or taking damage from an enemy unit (minions, champions, or neutral monsters), otherwise they're out-of-combat. Most out-of-combat effects trigger 5 seconds after being in-combat, resetting each time you're in-combat.
Champion abilities[]
Triggering combat effects[]
The following abilities trigger in-combat effects for the units hit at times where they do not visibly deal damage:
Anivia's 
Crystallize
Bard's 
Tempered Fate
Ezreal's 
Essence Flux (on application)
Trundle's 
Pillar of Ice
Yorick's 
Dark Procession
Zilean's 
Time Bomb (when it snaps onto an enemy)
Others[]
Annie's 
Summon Tibbers, when out-of-combat, grants Tibbers movement speed when moving toward Annie and restores health every second.- Bard's
Traveler's Call 
Evelynn's 
Demon Shade- For
Terrify's passive, 
Fiddlesticks has to be out-of-combat for 2.5 seconds so his other abilities 
fear enemies while he is unseen. 
Gnar's 
Rage Gene
Kayn's 
The Darkin Scythe
Rakan's 
Fey Feathers
Rek'Sai's 
Fury of the Xer'Sai, when out-of-combat for 8 seconds, Rek'Sai loses 20 fury per second.
Renekton's 
Reign of Anger, when out-of-combat for 12 seconds, Renekton loses 1 fury every 0,25 seconds.- All of
Rengar's 
Ferocity is lost after being out-of-combat for a few seconds. 
Taliyah's 
Rock Surfing and 
Weaver's Wall are disabled for a few seconds when in-combat.- Yorick's
Shepherd of Souls makes Mist Walkers proceed down the lane once they enter combat in that lane. 
Warwick's 
Blood Hunt- Zilean's
Time in a Bottle can only be used out-of-combat.
Items[]
Bami's Cinder, 
Sunfire Aegis, and 
Hollow Radiance are inactive while out-of-combat.
Jak'Sho, The Protean
Maw of Malmortius
Mosstomper Seedling
Riftmaker
Synchronized Souls
Unending Despair
Youmuu's Ghostblade
Runes[]
Neutral buffs[]
Others[]
Rift Herald opens its eye after being in-combat for a few seconds.
Super minions in ARAMs grant nearby allied champions a 20% movement speed boost while they are out-of-combat.
Special cases[]
The following effects do not trigger in-combat effects even if they do deal damage.
Shaco's 
Hallucination's basic attacks
