Delve

[Parcher]

Is it true that you cannot "over-Delve" any longer? That is, removing more cards fron the 'yard than are required to cast the spell.

[iamajellydonut]

Correct. A technical overhaul was applied to both Convoke and Delve as part of the M14 rules update.
http://archive.wizards.com/Magic/magazine/article.aspx?x=mtg/daily/feature/255c&page=3

"702.50 Convoke
I don't remember exactly how the conversation started, but one day a few months ago R&D ended up talking about how weird it was that you could "overtap" when casting a spell using convoke. That was weird, past-me thought, so I started thinking about ways to change that. As a cost-reduction ability, it couldn't really be contained. You can make a spell cost a billion mana less if you want to. I sought the advice of Rules Manager Emeritus Mark Gottlieb. Together, we came up with a new paradigm for convoke: what if instead of reducing the cost, tapping creatures was just another way of paying mana?

So now it is! You don't declare which creatures you're tapping ahead of time, just like you don't declare what lands you'll be tapping ahead of time. When it comes time to pay the spell's costs (rule 601.2g), you can tap creatures rather than pay mana. Note that this is after you have a chance to activate mana abilities (rule 601.2f). This means that if you intend to sacrifice a creature to activate a mana ability, you can't also tap that creature for convoke."

"702.65 Delve
Once we worked out the details of convoke, changing delve in a similar manner was natural."

[T-101]

Since this is another way of PAYING MANA, does this mean that Convoke and Delve spells can squeak through the Trinisphere?

I know that nothing has ever tricked the Trinisphere before, but that new verbiage has me wondering. These are no longer cost reductions, or alternate costs... they are paying mana, just in a different way.

[Dice_Box]

Yes, you can exile more cards to pay for increases in mana costs.

[cdr]

Since this is another way of PAYING MANA, does this mean that Convoke and Delve spells can squeak through the Trinisphere?

I know that nothing has ever tricked the Trinisphere before, but that new verbiage has me wondering. These are no longer cost reductions, or alternate costs... they are paying mana, just in a different way.

Basically yes, though since Delve and Convoke are paying mana, you're not technically tricking it. Trinisphere cares about the total cost, and the newer versions of Delve and Convoke do not affect the total cost and are not alternate or additional costs - they're the same as tapping a land. Feel free to Treasure Cruise for U + 7 exiled GY cards under Trinisphere.

702.65. Delve
702.65a. Delve is a static ability that functions while the spell with delve is on the stack. "Delve" means "For each generic mana in this spell's total cost, you may exile a card from your graveyard rather than pay that mana." The delve ability isn't an additional or alternative cost and applies only after the total cost of the spell with delve is determined.

[Julian23]

Am I correct to assume that Convoke is unaffected by Cursed Totem?

[vennie]

I believe so. Convoke does not give the ability to the creature as far as I know.

[iamajellydonut]

Am I correct to assume that Convoke is unaffected by Cursed Totem?

Convoke is as closely related to activated abilities as Devout Invocation is. Which is to say that it's not in any way.