If a player rolls a die, you can tap an untapped Wall you control to have that player reroll that die. Then, if you didn’t like that result, you can tap another untapped Wall you control in order to have them reroll again.

You decide whether to use Wall of Fortune’s ability right after you see the result of the die roll.

The Wall you tap to use Wall of Fortune’s ability can be one that came under your control this turn. This includes Wall of Fortune itself.

You can use Wall of Fortune to have a player reroll any die, including the planar die or the d20 from Sword of Dungeons & Dragons.