Evasion ability

An evasion ability is a kind of static ability of a creature that improves its chances of damaging the defending player by restricting which creatures can block it.

Types of evasion

The ultimate example is "This creature is unblockable" (e.g. Tidal Kraken), but there are several other evasion abilities:

• "Burrowing": Can't be blocked by creatures with flying e.g. Stone Spirit.
• Flying: Can only be blocked by other creatures with flying or reach e.g. Wild Griffin.
• Fear: Can only be blocked by Black or Artifact creatures e.g. Gluttonous Zombie.
• Intimidate: Can only be blocked by artifact creatures and/or creatures that share a color with it e.g. Bladetusk Boar.
• Horsemanship: Can only be blocked by other creatures with Horsemanship e.g. Lu Bu, Master-at-Arms
• Skulk: Can only be blocked by creatures with equal or lesser power e.g. Furtive Homunculus
• "Daunt": Can't be blocked by creatures with 2 or less power e.g. Arlinn's Wolf.
• Shadow: Can only block or be blocked by other creatures with Shadow e.g. Soltari Priest.
• Menace: Can only be blocked by two or more creatures e.g. Boggart Brute
• Landwalk: Unblockable if defending player controls a land with this property e.g. Rushwood Dryad.
• Specific 'Cannot be blocked by' clauses e.g. Sacred Knight, Vindictive Mob.
• Protection from X: Cannot be blocked by creatures with X quality e.g. Paladin en-Vec.

Pseudo-Evasion

Some abilities act as pseudo-evasion abilities, not affecting how creatures block but instead rendering the act of blocking partially or wholly ineffectual.

• Afflict: Deals life loss to the defender when blocked e.g. Ammit Eternal.
• Trample: Allows excess combat damage to be dealt to the defending player e.g. Force of Nature.
  • "Unstoppable": All combat damage is dealt directly to player e.g. Thorn Elemental.

Rules

From the glossary of the Comprehensive Rules (June 7, 2024—Modern Horizons 3)

Evasion Ability

An ability that restricts what creatures can block an attacking creature. See rules 509.1b–c.

From the Comprehensive Rules (June 7, 2024—Modern Horizons 3)

• 509.1b The defending player checks each creature they control to see whether it’s affected by any restrictions (effects that say a creature can’t block, or that it can’t block unless some condition is met). If any restrictions are being disobeyed, the declaration of blockers is illegal.
  A restriction may be created by an evasion ability (a static ability an attacking creature has that restricts what can block it). If an attacking creature gains or loses an evasion ability after a legal block has been declared, it doesn’t affect that block. Different evasion abilities are cumulative.

  Example: An attacking creature with flying and shadow can’t be blocked by a creature with flying but without shadow.

From the Comprehensive Rules (June 7, 2024—Modern Horizons 3)

• 509.1c The defending player checks each creature they control to see whether it’s affected by any requirements (effects that say a creature must block, or that it must block if some condition is met). If the number of requirements that are being obeyed is fewer than the maximum possible number of requirements that could be obeyed without disobeying any restrictions, the declaration of blockers is illegal. If a creature can’t block unless a player pays a cost, that player is not required to pay that cost, even if blocking with that creature would increase the number of requirements being obeyed. If a requirement that says a creature blocks if able during a certain turn refers to a turn with multiple combat phases, the creature blocks if able during each declare blockers step in that turn.

  Example: A player controls one creature that “blocks if able” and another creature with no abilities. If a creature with menace attacks that player, the player must block with both creatures. Having only the first creature block violates the restriction created by menace (the attacking creature can’t be blocked except by two or more creatures). Having only the second creature block violates both the menace restriction and the first creature’s blocking requirement. Having neither creature block fulfills the restriction but not the requirement.