Costs & Mana

Additional and alternative costs, cost changes, and why mana abilities don't use the stack.

The rules are CR 118 ("Costs"), CR 601.2 (the casting sequence — 601.2f is the total-cost formula) and CR 605 ("Mana Abilities").

A cost is an action or payment necessary to take another action. Costs are stricter than they look, and the order cost changes are applied in decides a surprising number of games.

Paying is all-or-nothing

A player can't pay a cost without the resources to pay it fully, and partial payments are never allowed. At 1 life you cannot pay 2 life. An already-tapped permanent can't be tapped for a cost. (At 2 life you can pay 2 life — you'll go to 0 and lose to a state-based action, but the payment itself is legal.)

Each payment applies to only one spell, ability or effect. You can't sacrifice one creature to pay two abilities that each require a sacrifice.

A cost of {0} is not automatic: it's paid by the player acknowledging that they're paying it. So "unless you pay {0}" is a genuine choice, and effects that care whether a cost was paid get a real answer either way.

A card with no mana cost at all has an unpayable cost — quite different from {0}. It can only be cast if something provides an alternative cost or casts it without paying its mana cost.

If effects change the actions you actually perform while paying, and what happens no longer matches what the cost called for, the cost has still been paid. A sacrifice cost is paid even if a replacement effect exiles the creature instead.

Additional vs alternative

• An additional cost is paid on top of the mana cost, at the same time. "As an additional cost to cast this spell, sacrifice a creature." They stack up.
• An alternative cost may be paid rather than the mana cost, and is usually optional. "You may pay … rather than pay this spell's mana cost." It replaces the mana cost entirely.

Hybrid and Phyrexian symbols are costs payable in more than one way, with the choice made when the cost is paid. Being payable several ways doesn't change the card's colour — a Phyrexian green symbol makes the card green whether or not you ever spend green mana.

The total cost formula, in order

Mana cost (or the chosen alternative cost), plus all additional costs and all cost increases, minus all cost reductions.

Increases before reductions is the part people get backwards, and it matters: a spell taxed {2} and reduced {1} nets +{1}. Reducing first could have hit the {0} floor and eaten the tax entirely.

When several reductions apply, you choose the order — worth actually thinking about when a reduction is proportional or conditional rather than a flat amount. The mana component bottoms out at {0}; it never goes negative and never produces mana.

Locked in

Once the total cost is determined and any effects that directly affect it are applied, the total is locked in. Effects that would change it afterwards do nothing.

This is why a tax effect must be on the battlefield before the spell is announced to matter at all — and why, once you have reached the payment step, an opponent can't tax you out of a spell you're already casting.

The casting sequence

Casting a spell follows a fixed order, and the order is examinable:

1. Move the card to the stack.
2. Announce modes, and any alternative or additional cost choices.
3. Announce targets.
4. Announce any division of an effect among targets.
5. The game checks the spell can legally be cast (if not, everything rewinds).
6. Determine the total cost.
7. Activate mana abilities — this is the window, and mana abilities must be activated before costs are paid.
8. Pay the total cost. Costs without random elements or library-to-public-zone movement first, in any order, then the rest. No partial payments.
9. Effects that modify the spell's characteristics as it's cast apply, and the spell becomes cast — now "whenever you cast" abilities trigger.

Targets are chosen before the total cost is determined, so a cost that depends on your target is calculated with that target already known. And once you've reached the payment step, you cannot back out.

Mana abilities

An activated mana ability may be used whenever you have priority, and also whenever you're casting a spell or activating an ability that needs a mana payment, or whenever any rule or effect asks for mana — priority or not. So announce the spell, then tap what you need during payment.

Mana abilities don't use the stack and resolve immediately, so they can't be targeted, countered or responded to. An ability that adds mana but requires a target is not a mana ability — it goes on the stack like anything else. A spell is never a mana ability, however much mana it makes.

27 questions in this track, checked against the 2026-06-19 Comprehensive Rules.

Rules covered: 106.4, 107.4, 107.4c, 107.4h, 118.3, 118.4, 118.5, 118.6, 118.7, 118.8, 118.9, 118.10, 118.11, 118.13, 202.1, 202.3, 202.3a, 202.3b, 202.3f, 500.4, 601.2, 601.2a, 601.2b, 601.2c, 601.2f, 601.2g, 601.2h, 602.2b, 605.1, 605.1a, 613.11, 712.8e.