How Manamancer Checks Format Legality

Selecting a format tells Manamancer which construction rules and card-legality field to apply. The result is not a single ban-list lookup: deck size, zones, copy counts, commanders, color identity, companions, restricted cards, and format-specific limits can all matter.

Last reviewed: August 2, 2026.

The fourteen supported formats

Some cards carry their own copy exception. Basic lands and cards whose Oracle text explicitly permits extra copies are handled before the ordinary format cap; named fixed-count cards such as Seven Dwarves and Nazgûl use their specific limit. A format's restricted-card rule can lower an otherwise four-copy card to one.

Where card legality comes from

For most formats, Manamancer reads the format legality recorded in its local Scryfall-derived card index. “Legal,” “not legal,” “banned,” and—where the format uses it—“restricted” are distinct source states. Search and validation use the same indexed card identities, reducing the chance that the builder and legality badge disagree because of a spelling or printing choice.

The index is a snapshot, not a live ruling feed. When a ban announcement, set release, or digital rebalancing changes a format, the imported data must refresh before the app reflects it.

Canadian Highlander is a special case because Scryfall does not publish a Canadian Highlander legality field. Manamancer uses the format's practical Vintage legal-or-restricted pool plus its own governing-list update path and a shared points provider. The official Canadian Highlander source remains authoritative when an event or a newly changed list is involved.

Pauper Commander also separates two ideas that are easy to conflate: legality in the 99 and eligibility to lead the deck. Commander eligibility comes from a dedicated imported roster rather than assuming that every card legal in the body can be a commander.

What full-deck validation checks

The format engine evaluates the current main deck, relevant competitive sideboard, command zone, and companion according to that format's definition. Depending on the format, checks include:

1. whether a required commander exists and the number of command-zone cards is allowed;
2. whether the total deck size is below, within, or above the permitted range — a Commander whose card text removes the maximum deck size is checked against the minimum only;
3. whether each commander is eligible and a two-card command zone is a valid pairing;
4. whether copies exceed the card-specific cap;
5. whether main-deck cards fit the combined commander color identity, including any exception the commander's own text grants for a named set of cards or for one extra color;
6. whether any card is banned or otherwise outside the format card pool;
7. whether a competitive sideboard is over its limit;
8. whether a companion fits its zone and deck-condition rules; and
9. whether a Canadian Highlander list exceeds its 10-point budget.

The maybeboard is a staging area and is not part of the submitted deck. It is therefore not used to make the deck legal or illegal. Commander does not use a competitive sideboard in Manamancer; constructed formats that do use one share their ordinary copy cap across the main deck and sideboard.

Legal, incomplete, and illegal

Manamancer exposes three summary states:

• Legal means the current resolved card data produced no construction violation.
• Incomplete means a required commander is missing or the deck is below its minimum size, with no illegal violation taking priority.
• Illegal means at least one ban, over-maximum size, invalid command zone, copy-limit problem, color-identity problem, points excess, or other construction failure exists. Illegal takes priority even when the list is also incomplete.

This distinction is useful while brewing. A 72-card Commander draft is incomplete, not condemned for containing too few cards; a banned card in that draft is still an illegal issue worth resolving immediately.

Warnings list offending card names when there are specific offenders. A size or points-budget warning may instead describe the deck-wide total. Cards still represented by unresolved loading records can delay an authoritative recomputation, so let a deck finish loading before treating its badge as current.

Interactive add checks

When you try to add a card, Manamancer uses a shorter decision path: banned status, card-pool legality, commander color identity, then the applicable copy limit. This explains why the interface may refuse a card before the finished deck has been run through every full-deck rule.

An add check cannot prove that the final list is legal. For example, a legal first copy can still leave the deck under its minimum size, and selecting two commanders can create a pairing issue that neither card has on its own. Use the full legality details after making structural changes.

Commander-specific details

A Commander head must be Commander-legal and have eligible front-face characteristics. Manamancer recognizes the current head families implemented by its rules engine: legendary creatures, eligible legendary Vehicles, eligible legendary Spacecraft with printed power and toughness, and cards whose text says they can be a commander.

A second commander is accepted only for supported pairing mechanics, including the matching Partner families, Friends forever, Background pairings, and Doctor's companion pairings. The combined color identity of the legal command-zone pair constrains the main deck.

Color identity is broader than mana cost. Symbols in relevant rules text and card characteristics can matter, while reminder-text and rules nuances are ultimately governed by Magic's rules. If a card seems incorrectly classified, check the current Oracle record and report the exact deck and card through the contact page.

Changing a deck's format

Changing format is not just changing a label. Manamancer previews the deck under the target rules and describes command-zone or sideboard changes. Leaving a command-zone format moves heads into the main deck; entering one clears stale head slots so the player can choose an eligible commander. The transition is designed not to delete cards, even when the result needs cleanup.

Search can show cards outside the active format when the format-legal filter is not selected. Those results are labeled off-format rather than hidden universally. This is useful when researching or preparing a format change, but it means “appeared in search” is not the same as “legal to add.”

What the badge cannot certify

A legal badge means the implemented checks passed against the currently loaded index and rules snapshot. It does not certify deck registration for a particular tournament. Manamancer does not know an organizer's house rules, a newly announced change that has not reached the index, marked-card or printing requirements, a submitted deck-list deadline, or every special event policy.

Before an event:

1. refresh the deck and review every legality detail;
2. compare any recent announcement with the official format source;
3. confirm companion and sideboard registration requirements; and
4. follow the tournament organizer's instructions.

Finally, the deck builder supports all fourteen formats, but Manamancer's AI Agent and AI generation are intentionally Commander-only. Do not use an Agent response as evidence that a Standard, Modern, Brawl, or other non-Commander deck is legal. See how the validated Commander Agent works for that narrower safety boundary.