MTG Convoke, Delve, Improvise, Affinity and Metalcraft guide image showing cost mechanics as fantasy scenes with creatures, graveyard magic, artifacts, cost reduction, and Commander rules energy.

MTG Convoke, Delve, Improvise & Affinity Guide

Four Magic: The Gathering mechanics let you cast expensive spells for less mana than they seem to require — and three of them do not actually reduce the cost at all. Add metalcraft to the mix, and you get the full rules package behind some of Magic's most explosive artifact, token, and graveyard decks.

That sounds like a technicality. It is not. It is the distinction that decides whether multiple copies of an ability stack, what happens when an opponent taxes your spells, whether a restriction on your mana applies, and what your spell's mana value is when it lands on the stack. Get it wrong and you will make an illegal play; get it right and you will find lines other players miss.

This guide covers convoke, delve, improvise, affinity, and the ability word metalcraft — with the rules text behind each and the interactions that come up at real tables.

This is the third article in our series on advanced MTG mechanics, following our guides to annihilator and the Eldrazi mechanics and cascade, storm and suspend.

The Distinction That Matters: Reducing vs Paying

Before any individual mechanic, understand the split. The four cost mechanics in this guide fall into two completely different categories, while metalcraft sits alongside them as an artifact-count condition.

Affinity genuinely reduces the cost. Affinity for artifacts on a spell costing {4} while you control three artifacts means the spell now costs {1}. The total cost itself is smaller.

Convoke, delve, and improvise change nothing about the cost. The spell still costs exactly what it costs. What they give you is permission to pay part of that cost with something other than mana — tapping creatures, exiling graveyard cards, or tapping artifacts. The rules are explicit that none of these is an additional or alternative cost, and that each applies only after the total cost has been calculated.

Three consequences follow immediately, and they are the ones judges get asked about:

  • Multiple instances behave differently. If a spell somehow has affinity twice, both instances apply and the reduction is doubled. If a spell has convoke twice, or delve twice, the second instance does nothing at all — they are explicitly redundant.
  • Tax effects hit them differently. If an opponent has an effect making your spells cost {1} more, that increase is part of the total cost — so you can convoke, delve, or improvise to pay that extra {1} as well. Affinity, being a reduction, is applied as part of calculating that same total cost.
  • Restrictions on spending mana do not apply. If an effect says you may spend only a certain kind of mana on a spell, that restricts mana. Tapping a creature for convoke is not spending mana, so the restriction simply does not reach it.

Keep that split in mind and every specific ruling below follows naturally.

Convoke

Convoke (CR 702.51) is a static ability that functions while the spell is on the stack. For each coloured mana in the spell's total cost, you may tap an untapped creature of that colour you control instead of paying that mana. For each generic mana in the total cost, you may tap any untapped creature you control instead.

Convoke is the most generous of these mechanics, because it is the only one that can pay for coloured mana.

The Rulings That Come Up

  • Summoning sickness is irrelevant. A creature that came down this turn can be tapped for convoke. You are not activating an ability with the tap symbol in that creature's own cost; convoke simply lets you tap an untapped creature you control while paying for the spell. This is one of the most useful things to know about convoke.
  • Multicoloured creatures pay for one colour. Tapping a two-colour creature pays for one mana of either of its colours, or one generic mana — your choice. It does not pay for two.
  • You cannot double-dip a creature. If you tap a creature for a mana ability while casting the spell, that creature is already tapped when you pay costs, so you cannot also convoke with it. The same applies if you sacrificed it for mana — it is no longer on the battlefield to be tapped.
  • You cannot tap more creatures than the cost requires. Convoke pays specific mana in the cost; there is nothing to gain from tapping extras.
  • Creatures tapped for convoke are tapped. Obvious, but it matters: they cannot attack or block, and they cannot be tapped again for anything else this turn.

Resolved Example

You cast a spell costing {5}{G}{G}. You control an effect making creature spells cost {2} less, and you have five untapped creatures — three green, two white — one of which entered this turn.

First calculate the total cost: {5}{G}{G} reduced by {2} becomes {3}{G}{G}. Now convoke applies to that total. You tap two green creatures to pay the {G}{G}, and three creatures of any colour to pay the {3} — including the one with summoning sickness. Total mana spent: zero.

Improvise

Improvise is convoke's artifact cousin, and the difference is important: for each generic mana in the spell's total cost, you may tap an untapped artifact you control instead of paying that mana.

Generic only. Improvise can never pay for a coloured mana symbol, no matter what artifact you tap. That is the single most common improvise mistake, and it is the reason convoke is generally the stronger of the two — plenty of improvise cards have coloured costs that improvise itself cannot help with.

Everything else works similarly to convoke: it is not an alternative cost, it applies after the total cost is calculated, and artifacts that entered this turn can be tapped for improvise. Even artifact creatures with summoning sickness can be tapped this way, because you are not activating one of their own abilities with the tap symbol.

Delve

Delve (CR 702.66) does the same job with your graveyard: for each generic mana in the spell's total cost, you may exile a card from your graveyard instead of paying that mana.

Again, generic only — delve cannot pay coloured costs. And again, it is not an alternative cost and applies after the total cost is determined.

The Rulings That Come Up

  • You exile as you pay. The cards leave your graveyard at the moment you pay the spell's costs — not earlier, not later. That timing matters if something in the game is watching for cards leaving your graveyard.
  • The cap is the generic portion. A spell costing {6}{U}{U} lets you exile at most six cards. You cannot exile more to "save" anything.
  • Multiple instances are redundant. Delve twice on one spell does nothing extra.
  • You can delve away a tax. If an opponent's effect adds generic mana to your spell's cost, that added mana is part of the total cost — so you can exile graveyard cards to pay for it.
  • Delve used to work differently. When it first appeared in Future Sight, delve genuinely reduced the cost. It was rewritten when it returned in Khans of Tarkir to the payment-method version we have today. If you read old articles about delve, this is why they may not match the current rules.

Affinity

Affinity (CR 702.41) is the one that really is a discount. "Affinity for [something]" means the spell costs {1} less to cast for each of that something you control.

The Rulings That Come Up

  • It only reduces generic mana. Affinity can never reduce the coloured portion of a cost. A spell costing {4}{U}{U} with affinity for artifacts and six artifacts in play still costs {U}{U} — the {4} is gone, the blue is not.
  • It cannot reduce below zero. There is no such thing as a negative cost, and you do not gain anything for excess.
  • Multiple instances all apply. This is the crucial difference from convoke and delve. If a spell has affinity for artifacts twice, both reductions happen. If a card grants affinity to a spell that already has it, both apply.
  • It does not change the mana cost or mana value. The card still has the mana value printed on it, however little you paid.

Metalcraft

Metalcraft is different in kind from the other four: it is an ability word, not a keyword ability. Ability words have no meaning in the rules at all — they are italicised labels that group similar cards together for flavour. The actual rules text is always written out on the card.

What metalcraft cards share is a condition: they do something extra as long as you control three or more artifacts. Sometimes that is a bigger creature, sometimes an extra ability, sometimes permission to activate something.

Two details worth knowing:

  • An artifact permanent with metalcraft counts itself. If the metalcraft card is an artifact permanent on the battlefield, it is one of your three artifacts. So an artifact with metalcraft only needs two other artifacts alongside it.
  • Because there is no keyword rule, read the card. Each metalcraft card spells out its own condition and effect, and they are not identical across cards.

The most famous metalcraft card is Mox Opal, a zero-cost legendary artifact that taps for one mana of any colour — but only while you control three or more artifacts. It counts itself toward that three, which is why artifact decks can turn it on so quickly.

There is a lovely rules trap on Mox Opal worth knowing, and it comes from the legend rule rather than from metalcraft: if you control a Mox Opal plus one other artifact, and a second Mox Opal enters as your third artifact, you never get to use either one. The legend rule is a state-based action, so it is checked and one Mox Opal is put into its owner's graveyard before any player receives priority to activate a mana ability. You are back to two artifacts, and metalcraft was never on.

None of These Change Mana Value

This deserves its own section because it catches people constantly. Convoke, delve, improvise, and affinity all leave the spell's mana value unchanged.

A spell that costs {6} and is cast by tapping six creatures with convoke still has mana value 6. A spell reduced to nothing by affinity still has its normal mana value. What changed is what you paid — not what the card is.

That has real consequences:

  • An effect that counters spells with mana value 4 or greater still counters your "free" spell if its printed mana value qualifies.
  • Cascade cares about mana value, so a spell you paid nothing for still cascades into whatever its printed value allows — as we cover in our cascade, storm and suspend guide.
  • Anything checking mana value on the stack, in the graveyard, or in exile sees the card's mana value, not the amount you paid. The usual X-spell exception still applies: if a spell has X in its mana cost, X has the chosen value while that spell is on the stack, and counts as 0 in every other zone.

Quick Reference: Cost Mechanics Compared

Question Convoke Improvise Delve Affinity
What do you use? Tap creatures Tap artifacts Exile graveyard cards Nothing — it's a discount
Can it pay coloured mana? Yes, with a creature of that colour No No No — generic only
Does it reduce the cost? No No No Yes
Do multiple instances stack? No — redundant No — redundant No — redundant Yes — each applies
Does it change mana value? No No No No
Can it pay a cost increase? Yes Yes (generic) Yes (generic) Applied when calculating the total

Why These Matter in Commander

Convoke turns a wide board into mana. In a token or go-wide deck, a board of creatures you were not going to attack with is a pile of unused resources. Convoke converts it directly into casting power, and because it can pay coloured costs it works even in demanding colour requirements. It also plays beautifully with creatures that entered this turn, which is precisely when a token deck has the most bodies.

Delve rewards a full graveyard, and competes with it. The tension is real: graveyard-based Commander decks want cards in the yard, and delve wants to exile them. Running several delve spells in the same deck means they fight over the same fuel. Delve is also the mechanic most vulnerable to graveyard hate — an opponent exiling your graveyard turns a one-mana spell back into an eight-mana one.

Affinity and metalcraft are why artifact decks snowball. Each artifact you deploy makes the next spell cheaper and turns on more conditions. That is a genuine engine, and it is also why artifact removal and mass artifact destruction hit those decks so much harder than they look.

You can find the pieces for these strategies in our full catalogue, or import your decklist directly with our decklist search tool.

Frequently Asked Questions

Can I tap a creature that just came into play for convoke?

Yes. Summoning sickness stops a creature from attacking and from using abilities with the tap symbol in their cost, but convoke does neither of those things — the convoke ability taps the creature as an effect. Any untapped creature you control is fair game regardless of when it arrived.

Can convoke pay for coloured mana?

Yes, and this is convoke's main advantage. A creature of a given colour can pay one mana of that colour. A multicoloured creature pays for one mana of any one of its colours, or one generic mana — your choice, but only one.

Can improvise or delve pay for coloured mana?

No. Both work only on the generic portion of a spell's total cost. A spell costing {3}{U}{U} can have the {3} paid by tapping artifacts or exiling graveyard cards, but the {U}{U} must be paid with actual blue mana.

Does convoke or delve reduce my spell's mana value?

No. Neither does affinity or improvise. All four change what you pay, not what the card is. A spell's mana value comes from its mana cost, not from the amount of mana you actually spent — which matters for counterspells that check mana value, for cascade, and for any other effect that cares.

If a spell has affinity twice, do both apply?

Yes. Multiple instances of affinity each apply, so the reductions add together. This is different from convoke, delve, and improvise, where multiple instances on the same spell are explicitly redundant and the extras do nothing.

Can affinity make a spell free?

It can reduce the generic portion of the cost to nothing, so a spell whose cost is entirely generic can end up costing {0}. It cannot go below zero, and it can never reduce coloured mana requirements — those always have to be paid.

What exactly is metalcraft?

An ability word marking cards that do something extra while you control three or more artifacts. Ability words have no rules meaning of their own — the real rules text is written out on each card — so metalcraft cards are not all identical. If the metalcraft card is itself an artifact, it counts toward its own three.

Does an opponent taxing my spells stop me convoking or delving?

No — in fact those mechanics help you pay the tax. A cost increase becomes part of the spell's total cost, and convoke, improvise, and delve all apply after the total cost is calculated, so you can use them to cover the extra generic mana as well.

More guides in our advanced mechanics series:

The keyword abilities series:

Related guides:

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