How would you rule “secret casting”?

@ptr_mlr How would you rule “secret casting”? A) Out in the open? B) While already hidden? Different checks for V, S, M components? already hidden, would require another Stealth check vs. passive perception

— (((Mike Mearls))) (@mikemearls) August 22, 2016

@ptr_mlr @ChrisPerkinsDnDThanks! Would you allow that to avoid combat? E.g. a hidden AT Rogue casts Silent Image to distract a target? yes, that sound reasonable

— (((Mike Mearls))) (@mikemearls) August 23, 2016