Breaking Lamp
Instantly destroying Baptiste's Immortality Field turret to remove the protection and kill through what would otherwise be prevented.
Lamp isn't an ult, but it protects a fight the way a defensive ult does, so an engage plan decides in advance who is responsible for breaking it. Without assigning damage that can actually break it (a tank's instant burst or sniper-class damage), a Wombo Combo's damage is reduced to zero by a single Lamp. Including the retreat call for when you fail to break it, this is the crux of the micro: the three options are to focus it down instantly the moment it's placed, wait for it to expire, or disengage entirely.
Checking for Lamp before committing a Wombo Combo, and if it's up, assigning the breaker first. The breaker focusing it down the instant it's placed.
Pushing without noticing Lamp, so the Wombo Combo gets nullified on everyone. No breaker was assigned, nobody puts damage on Lamp, and the fight is spent for nothing.
Wombo Combo
Stacking multiple ultimates within one second to bypass defensive cooldowns and wipe the team.
Resource Trade
Spending a minor cooldown to force a major defensive one, netting an advantage for the real fight.
Crossfire
Two or more shooters hitting the same target from divergent angles so no single piece of cover blocks both.
Pre-fire
Pre-aiming a known spawn point or pathing route to win the first frame of contact.
Breaking Suzu
Baiting out Kiriko's Suzu (invulnerability + cleanse) and then bursting through the window the instant it expires.