Today, we’re going to be covering some of the shortcuts that deal with casting spells and activating abilities. There are a few, so let’s dive right in:

–Whenever a player adds an object to the stack, it’s assumed that player is passing priority unless he or she declares intent to retain it. For example, if you cast Fireball and want to copy it with your Reverberate, you’ll need to retain priority. If you pass priority and your opponent has no response, it’s too late to Reverberate the Fireball, as it’s already off the stack.

–If a player adds a group of objects to the stack without explicitly retaining priority and another player wants to respond at some point in the middle, the game is rewound back to that point. For example, if I pump my Nantuko Shade seven times and you want to Sudden Shock it after the first activation resolves, we rewind to that point. I get to untap the lands for the other six activations, etc.

–If a player casts a spell or activates an ability with X in its mana cost and doesn’t specify a value for X, then X is assumed to be the highest possible value payable with the mana in that player’s mana pool. For example, if I cast Green Sun’s Zenith by tapping ten Forests, but I know you have a Mana Leak in hand, I need to announce that X=6, otherwise I’m casting it with X=9. (Did you know that you’re required to announce what mana is in your mana pool whenever you pass priority?)

–Whenever a player casts a spell or activates an ability that targets an object on the stack, it targets the legal target closest to the top of the stack unless its controller announces otherwise. For example, if you cast Fireball followed by Reverberate, and then I cast Mana Leak without announcing a target, the Mana Leak is targeting the Reverberate.

Today’s Rules Tip was provided by Charlotte Sable, a level 2 judge from Ontario, Canada.