Additional cost: discard v. copying

by **Korath** » 16 Dec 2021, 20:33

Describe the Bug:
Copying cards with "As an additional cost to cast this spell, discard [a specific number of cards, maybe of a specific type] [maybe at random]" makes you pay the additional cost.

Fixture: Four Mountain on the bf; a Sonic Burst and three Fork in your hand. Cast the Sonic Burst for {R}

and discard a Fork, cast a second Fork targeting the Sonic Burst.
Observed: You discard your third Fork when the copy of Sonic Burst is put on the stack.

Which update are you using? (date, name)Which type? (duel, gauntlet, sealed deck)
dev 58bc91e3e.

What exactly should be the correct behavior/interaction?
Expected: You still have the third Fork in your hand after the first Fork resolves.

Copying objects on the stack doesn't make you pay any of their costs. (If the choices you made while paying them affects resolution, those choices are copied per rule 707.2.)

Are any other cards possibly affected by this bug?
I've only looked at Sonic Burst and Wild Guess. Unlike the other two bugs I'm reporting with "additional cost: discard" today, it's likely card-specific. It's also just as likely to affect any given additional cost, not just discarding.