You may pay rather than pay the mana cost for spells you cast.
"Willem put it on and started shooting sparks from his hands like some kind of wizard! Was supposed to be my turn next, but the blasted thing won't come off his hand. Send help."
—Brazen Coalition expedition dispatch
If you pay {W}{U}{B}{R}{G} rather than pay the mana cost of a spell with {X} in its mana cost, the only legal choice for X is 0.
01-12-2004
wotc
If you apply Fist of Suns's alternative cost to a spell with {X} in its mana cost, X is 0.
01-12-2004
wotc
Fist of Suns's ability is an alternative cost to cast a spell. You can't combine this with other alternative costs, such as flashback. You can pay additional costs, such as kicker, in addition to this alternative cost.
01-12-2004
wotc
If you cast a spell for which mana of any color can be spent to cast it, you may cast it for Fist of Suns's alternative cost and still spend any color of mana to cover that cost.
Random a card of Magic: The Gathering (MTG), but you can also roll the D20 dice, random a Planeswalker, have fun with the random rules and more.