take back

It depends — there's no universal "take back" in Riftbound; whether you can reverse an action comes down to organized play level and whether anything new has happened since.

Once an action is communicated to an opponent it generally can't be taken back (Rule 509.2). At Low OPL you may reverse your most recent action as long as no new action has been taken by either player; at High OPL that's narrowed to immediately after the choice, and only for things like spell/ability choices, unit/gear placement, moves/discards, or rune exhaust-recycle decisions (509.3–509.4). Any new action by either player closes the window.

Two hard limits: you can't reverse based on an opponent's reaction or to gain information (that's Angle Shooting, 509.5/704.4), and take-backs are for fixing illegal game states, not for correcting a legal but bad decision — a judge can't rewind a legal misplay just because you forgot about an opponent's trigger. In casual play it's whatever the table agrees to; if it's borderline in a tournament, call a judge.