Mana Siphoon vs. Divine Intervention

[Boocheck]

Here is the situation.

Player A, casted mana Siphoon.
Player B revelead Divine Intervention during casting steps and teleport himself out of reach.

Is now Player A forced to choose himself as a terget?

I would say no, and that there is standing a Mana Siphoon without purpouse but i would like to have it official or at least Zuberized

[Zuberi]

[mwcard=MW1J14]Mana Siphon[/mwcard] is not optional. You have to choose a Mage to suffer from it, and if your own mage is the only one within range then so be it. I have used this trick myself and my opponent was quite displeased.

Edit: Check out page 41 of the Rules Supplement for further details.

[Zuberi]

P.S. I feel quite honored to have been made into a verb, lol.

[iNano78]

[mwcard=MW1J14]Mana Siphon[/mwcard] is not optional. You have to choose a Mage to suffer from it, and if your own mage is the only one within range then so be it. I have used this trick myself and my opponent was quite displeased.

Edit: Check out page 41 of the Rules Supplement for further details.

So the argument is that since the opposing mage is no longer a legal target, you must select your own mage. I thought you would still choose the other mage, who is no longer a legal target due to range, and the effect of the spell would fizzle. But this seems to have a ruling that if there exists another legal target, you must select another target. Why doesn't that apply to other spells? For instance, if I cast an incantation or enchantment (or conjuration that attaches to an object) and the target becomes illegal, why am I not forced (or allowed) to choose another (legal) target if it exists? Is it because Mana Syphon's "target" is really a zone (that remains legal) and the mage is specified in the spell's text, applying after the spell has resolved, rather than as a condition of the spell resolving (as the target of the spell itself, in the case of incantations/enchantments/attached conjurations).

[Kharhaz]

Is it because Mana Syphon's "target" is really a zone (that remains legal) and the mage is specified in the spell's text, applying after the spell has resolved, rather than as a condition of the spell resolving (as the target of the spell itself, in the case of incantations/enchantments/attached conjurations).

That pretty much sums it up.

[Laddinfance]

Zuberi is correct. When a Mana Siphon is brought into play, you must have it target a Mage within two zones and LOS. If your Mage is the only eligible target, then they have to get Siphoned.

[Hardcordo]

That is dirty...I like it.

[Kharhaz]

Zuberi is correct. When a Mana Siphon is brought into play, you must have it target a Mage within two zones and LOS. If your Mage is the only eligible target, then they have to get Siphoned.

If there are no targets, lets assume that both mages [mwcard=MW1E11]Divine Intervention[/mwcard] away before it resolves, at the end of step 2 (counter) but before step 3(resolve)

It would remain in play and resolve without a target for its ability, occupying a zone and wasting everyone time

[Zuberi]

So the argument is that since the opposing mage is no longer a legal target, you must select your own mage. I thought you would still choose the other mage, who is no longer a legal target due to range, and the effect of the spell would fizzle. But this seems to have a ruling that if there exists another legal target, you must select another target. Why doesn't that apply to other spells?

The short answer is that this does apply to other spells and abilities. When you cast a spell, you choose your target during the Cast Spell Step. You can not choose an illegal target during this step, and you do not have to spend mana nor commit to the spell until you have chosen a legal target. So, if the target that you wanted to select is shown to be illegal right away, then you are allowed to choose a different target (and you have to if you still want to cast the spell), or you could even cast a different spell or perform a different action all together. It's only after you've selected a legal target and finished the Cast Spell Step that you are committed to your decisions. (English Rules v3 page 13)

At that time, once the Cast Spell Step is completed, if the target then BECOMES illegal it is too late for you to back out. So, you can not choose a different target or action, the spell will be cancelled, and you will forfeit all investment you've put into casting it.

The same is true with attacks, which select a target during the Declare Attack Step (English rules v3 page 23), and any other ability that selects a target. You can not choose an illegal target when you initially select a target for anything. Rules for cancelling an effect due to an illegal target are intended for when your legal target choice somehow becomes illegal.

Now, with Mana Siphon, you do not select the target for it's ability until the Resolve Spell Step. In this scenario, your opponent teleported away before this step, so when it comes time for you to select a target of the ability your mage is the only legal one available and you MUST select a legal target, ie yourself, because the effect is not optional and the spell was successfully cast. It does not cause the spell to be cancelled, because the opponent was not a target for the spell cast, just the spell effect. The opponent was never a part of the spell at all, having teleported away before it became time to select a target for the effect. It's not that they became an illegal target so much as the fact that they were NEVER a target of the spell to begin with.