Hello! Can a player use Gideon's Resolve and search for the planeswalker even if he knows that the card is not in the deck? I mean, can he use it just to shuffle the library?
Level 4 Judge (Judge Foundry), Hall of Fame, Judge
USA - Southwest
Gideon's Resolve search
Yes, that's allowed; many search effects allow you to fail to find. (The exception is when searching for a number of cards, but not a specific type or other characteristic.)