Otto's Irresistible Dance has following effect/end condition:
As an action, a dancing creature makes a Wisdom saving throw to regain control of itself. On a successful save, the spell ends.
I'm unsure how to interpret the indicative(?) mood "makes" here. Is this action optional, "can choose to make", or is it compulsory, "is forced to make", and why?
This's QA suggests it is optional, but none of the answers explain why. My naive reading of the text suggests making the saving throw action happens, ie. to me it sounds like there is no option for it to not happen. So this leaves me confused.
I haven't cast the spell yet, and the DM may of course make their own ruling for this campaign, but I still want to know the correct RAW interpretation. None of us are native English speakers.