Ah, 2008. The global housing market crashed. Bitcoin was introduced to an unsuspecting world. The summer Olympics were held in Beijing. And an experiment was happening in a little game called Magic: the Gathering, where rather than a three-set block, we were getting two sort-of-adjoined two-set blocks with Lorwyn and Shadowmoor. Shadowmoor debuted in April, and brought with it a funny little mechanic called Conspire.

A cult of conspiracy arises

Conspire is a keyword mechanic, which means it's a word which stands in for either a single action or series of actions. In this case, it means two things:

1) A static ability which functions while it's on the stack that says "As an additional cost to cast this spell, you may tap two untapped creatures you control that each share a color with it" (Comp. Rules 702.78a)

2) A triggered ability which says "When you cast this spell, if its conspire cost was paid, copy it. If the spell has any targets, you may choose new targets for the copy". (Comp. Rules 702.78a)

That's a really complicated way of saying when you cast a spell with Conspire, you may tap two Creatures you control which must share a color with the spell. If you do, you get an extra copy of the spell.

One fun rules advantage is you can actually tap a Creature with summoning sickness to pay for Conspire, because it's the card with Conspire tapping the Creature, not attacking. That can be quite helpful!

When you want something, all the universe conspires in helping you to achieve it

Conspire exists on 11 total cards, 10 of which are from Shadowmoor, and has a Storm Scale rating of 8, so we're unlikely to see much more of it. We did get a random spell in the Lord of the Rings Holiday Release in Rally the Galadhrim.

The mechanic is fairly broadly considered a failure. According to Mark Rosewater, reception was poor (with no further information).

That doesn't make it any less complicated, though. Let's go through the special cases.

Once you make a decision, the universe conspires to make it happen

Many of the Conspire spells are multicolored. When you cast one, the two Creatures you tap don't have to share a color with each other, just with the spell with Conspire. So if you're copying Giantbaiting, you can tap a Llanowar Elves and a Goblin Guide.

You can only pay Conspire costs once per instance of Conspire. If a spell gets multiple instances of Conspire somehow, you can pay for each of them once (with different pairs of Creatures!) but not more. In a weird quirk of the rules, the copy of the spell with Conspire also has Conspire, but you can't use it because you didn't cast that spell.

The copy created by Conspire functions like a normal copy. It is its own spell and must be countered or otherwise interacted with separately. If someone counters the original spell with Conspire, the copy still resolves. Similarly, should the Triggered Ability spell be countered with something like Stifle, the original spell is still cast and will still do its normal thing.

An Organized Conspiracy

Two cards grant Conspire to different groups of cards.

Wort, the Raidmother came out in Shadowmoor along side the other spells with Conspire and grants Conspire to all your Red and Green Instants and Sorceries. This can be very powerful when done correctly - "I'm going to tap these two Green Saprolings to copy Natural Order, then sacrifice them both to go get these, I don't know, Avenger of Zendikar and Ghalta. Sound good?"

Rassilon came out in Doctor Who and grants Conspire to all the noncreature spells you cast from Exile. Again, built correctly this can have quite the effect, but you'd better be prepared to manipulate the top of your Library to make it work.

And that's it. Everything (and probably more) that you ever wanted to know about Conspire.

Thanks for reading.