Animation Cancel
Cutting an ability's recovery animation with another action to move into your next action faster than the animation normally allows.
On heroes with recovery frames after an action, you input a different action to shorten that recovery and bring the next action forward. Cutting a Reinhardt hammer swing with Fire Strike to speed up the follow-up, or cancelling Doomfist's Seismic Slam with another action to carry momentum straight into a reposition — it is treated as a collective concept covering hero-specific techs. Its tactical value sits on three axes: becoming harder to react to reliably, changing travel distance, and shortening the interval between consecutive actions; shortening recovery during an Ult in particular can be effective. Individual techs can have their behavior changed by OW2 updates, so whether one works on the current patch has to be verified each time. The safe approach is to learn it as a concept and to pick up hero-specific execution while cross-checking the patch notes.
On Reinhardt, input Fire Strike right after a hammer swing to cut the swing recovery and speed up the follow-up. On Doomfist, cancel Seismic Slam with another action to reposition while keeping momentum. Broadly, any situation where inserting another action at a specific timing after an ability shrinks the enemy's guaranteed reaction window.
Continuing to use a tech whose behavior changed in a patch, so the cancel does not register and the timing is thrown off instead. Or inputting the wrong action while going for the cancel and whiffing an ability you never meant to spend.