Rules Tip of the Day: When paying the costs of a spell or ability, you must pay the entire cost. You cannot choose to pay a portion of a cost in order to avoid mana burn.

Q: Does the effect of Dunerider Outlaw work for every point of damage it deals, or just get one counter every turn?

A: Regardless of the amount of damage that a Dunerider Outlaw has dealt to an opponent this turn, its ability will only trigger once, at the beginning of the end of turn step, and it will only get a single +1/+1 counter.

Q: Player A is at six life, and has Krosan Grip in hand and the mana to cast it. It is currently Player B's first main phase and he has a Seismic Assault in hand along with the mana to play it, as well as having three lands in his hand. Player B plays Seismic Assault. Player A has no responses, so it resolves. Now, Player B has priority again immediately following the resolution of the Seismic Assault. Is he able to use each of the three lands in his hand to activate Seismic Assault's ability in succession, without passing priority, before Player A has priority to play his Krosan Grip?

A: Yes, after a player plays any spell or ability, that player will immediately receive priority again. A single player can add something to the stack and then—before anyone else can play anything—play something else. Usually, a player will play a single spell or ability and then pass priority to their opponent, but they do not have to. Keep in mind that passing priority is the general practice, and that if a player does not specify that they wish to keep priority after playing a single spell or ability, it is assumed that they pass priority.

Q: If my oponent plays his Vesuvan Shapeshifter face-up, copying my Teferi, Mage of Zhalfir, will I still get a chance to play Boomerang on the Shafeshifter to save my Teferi?

A: No, your opponent will choose what to copy when the Shapeshifter spell resolves and comes into play. If you pass priority and allow this Shapeshifter spell to resolve, then your opponent can choose to copy your Teferi. This Shapeshifter copy of Teferi will enter play and state-based effects will be checked immediately afterwards. At this point, both the original Teferi and the Shapeshifter copy will go to the graveyard due to the legend rule. To save your Teferi (albeit most likely temporarily) you could have responded to the Shapeshifter spell with Boomerang targeting your Teferi. Then when the Shapeshifter came into play your opponent would have had to choose a different creature in play to copy, if there was one available. Keep in mind that if this Shapeshifter did enter play as some other creature and you did replay your Teferi, the Shapeshifter could always be turned face-down in the upkeep of its controller and then copy your Teferi by turning face-up. This would end up causing both to go to the graveyard.

Q: My opponent has Dark Depths in play with ice counters on it. I play Phantasmal Terrain, turning it into a basic land. Can he still remove counters from it and use its ability? Or is it now just a basic land?

A: When a land "becomes a [basic land type]", it loses all abilities and will only have the appropriate mana ability associated with that basic land type. This Dark Depths will keep the ice counters on it, will not have the ability to lose ice counters, and will not have the triggered ability that puts a 20/20 token creature into play when all ice counters are removed from it.

Q: My opponent has Eight-and-a-Half-Tails. I have Volrath's Shapeshifter and Survival of the Fittest in play. I use Survival of the Fittest to discard Shauku, Endbringer and search for Iridescent Angel. Now that Volrath's Shapeshifter is Shauku, Endbringer, I tap it to remove Eight-and-a-Half-Tails from the game. Naturally, my opponent uses both of Eight-and-a-Half-Tails' abilities first, giving itself protection from white and targeting the Shapeshifter to make it a white permanent. Three abilities are now on the stack. I answer by using Survival of the Fittest to discard Iridescent Angel to search for another creature. Nothing else is played, and everything starts to resolve. Volrath's Shapeshifter now has protection from all colors. Next, Eight-and-a-Half-Tails' ability to make my creature white "fizzles." Then, Eight-and-a-Half-Tails gains protections from white. At this point, my opponent claims that the first ability on the stack (the Shauku ability) will now "fizzle" because Eight-and-a-Half-Tails has protection from white, and the Shapeshifter, at this point, counts as a white creature, per the color traits of Iridescent Angel. I argue that the effect is already on the stack, and is not a white ability—the fact that the creature has changed colors does not change the outcome of this resolution. Who is correct, and why?

A; Your opponent is. Abilities do not have colors, they have sources. The source of this ability when it resolves is the Volrath's Shapeshifter / Iridescent Angel permanent in play. This means that the source of this ability is white. It does not matter that when the ability was played the permanent was a black Volrath's Shapeshifter / Shaku, Endbringer.

Q: I thought that all activated abilities used the stack, so a response to someone sacrificing a Terramorphic Expanse would be to Boomerang it back to their hand. But then someone said that sacrifices don't go on the stack. Does that mean that Voidmage Prodigy's ability doesn't go on the stack either?

A: It is not that sacrifices do not go on the stack, but the payment of costs are made when an spell or activated ability is announced, and no one can respond to the payment of costs. In this example, the Terramorphic Expanse is sacrificed when its ability is used. By the time you receive priority to play anything, the Terramorphic Expanse is no longer in play and cannot be targeted. The abilities of Terramorphic Expanse and Voidmage Prodigy do use the stack, but paying the costs of these activated abilities do not. You can still counter these abilities with effects that counter abilities, but you cannot disrupt these abilities by preventing the payment of costs after they have been paid for.

Q: With regards to Pyroblast and Red Elemental Blast, I know that it's not possible to destroy a permanent unless it's blue, but can you target it anyways for something like Storm count? The way I read it is "destroy target permanent if it's blue", but if it's not blue, then nothing would happen? Is it illegal to target a green creature altogether?

A: You can target non-blue objects with Pyroblast, but not Red Elemental Blast. These two spells are similar but they do have very distinct and different texts. Pyroblast can target any spell or permanent; that is its only targeting restriction. If the targeted spell or permanent is not blue when Pyroblast resolves, nothing will happen. Red Elemental Blast is different; it can only target a blue spell or permanent. In order to play Red Elemental Blast there must be a blue spell or blue permanent to target.