Daybound and Nightbound

Daybound (Nightbound)
[[File:{{#setmainimage:MTGA DayNight.png}}|70x70px]]
Keyword Ability
Type	Static
Introduced	Innistrad: Midnight Hunt
Last used	Alchemy: Innistrad
Reminder Text	Daybound (If a player cast no spells during their own turn, it becomes night next turn.) Nightbound (If a player cast at least two spells during their own turn, it becomes day next turn.)
Storm Scale	6
Statistics	35 Daybound cards 2.9% 2.9% 11.4% 37.1% 34.3% 11.4% 35 Nightbound cards 11.4% 40% 37.1% 11.4%
Scryfall Search
keyword:"Daybound" keyword:"Nightbound"

Daybound and Nightbound are a pair of keywords introduced in Innistrad: Midnight Hunt and also used in Innistrad: Crimson Vow.

Description

Day marker

Night marker

Daybound and Nightbound are static abilities.

When the game starts, it is neither day nor night. The most common way for this to change is for it to become day as a permanent with daybound appears on the battlefield. This occurs as the permanent enters the battlefield and does not use the stack. Spells and abilities can also explicitly cause it to become day or night.

Once it's day or night, the game will be exactly one of those designations, day or night, until the game ends. A game cannot lose its day/night designation entirely, and the designation is the same for all players.

If it's day, transforming double-faced cards with daybound and nightbound enter the battlefield with its daybound face up. If it's night, they enter nightbound face up. Note that cards with daybound/nightbound have the characteristics of their front (daybound) face while they are spells on the stack, even if it is currently night.

There are two ways for the game's day/night designation to change. If it's day as a turn begins, and the previous turn's active player didn't cast a spell last turn, it becomes night. Similarly, if it's night as a turn begins, if the previous turn's active player cast two or more spells last turn, it becomes day.

As it becomes day, all double-faced cards with nightbound transform to their daybound faces. As it becomes night, all double-faced cards with daybound transform to their nightbound faces. This does not use the stack, and is not a state-based action. Permanents with daybound and nightbound can't transform any other way.

To help players keep track of day and night, a helper card that reminds you of these rules is inserted into some booster packs of the relevant sets.

Rules

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

Daybound

An ability found on the front faces of some double-faced cards. Cards with daybound and nightbound are face up when it’s day and face down when it’s night. See rule 702.145, “Daybound and Nightbound,” and rule 727, “Day and Night.”

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

Nightbound

An ability found on the back faces of some double-faced cards. Cards with daybound and nightbound are face up when it’s day and face down when it’s night. See rule 702.145, “Daybound and Nightbound,” and rule 728, “Day and Night.”

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

• 702.145. Daybound and Nightbound
  • 702.145a Daybound and nightbound are found on opposite faces of some transforming double-faced cards (see rule 712, “Double-Faced Cards”).
  • 702.145b Daybound is found on the front faces of some transforming double-faced cards and represents three static abilities. “Daybound” means “If it is night and this permanent is represented by a transforming double-faced card, it enters the battlefield transformed,” “As it becomes night, if this permanent is front face up, transform it,” and “This permanent can’t transform except due to its daybound ability.” See rule 727, “Day and Night.”
  • 702.145c Any time a player controls a permanent that is front face up with daybound and it’s night, that player transforms that permanent. This happens immediately and isn’t a state-based action.
  • 702.145d Any time a player controls a permanent with daybound, if it’s neither day nor night, it becomes day.
  • 702.145e Nightbound is found on the back faces of some transforming double-faced cards and represents two static abilities. “Nightbound” means “As it becomes day, if this permanent is back face up, transform it” and “This permanent can’t transform except due to its nightbound ability.”
  • 702.145f Any time a player controls a permanent that is back face up with nightbound and it’s day, that player transforms that permanent. This happens immediately and isn’t a state-based action.
  • 702.145g Any time a player controls a permanent with nightbound, if it’s neither day nor night and there are no permanents with daybound on the battlefield, it becomes night.

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

• 728. Day and Night
  • 728.1. Day and night are designations that the game itself can have. The game starts with neither designation. “It becomes day” and “it becomes night” refer to the game gaining the day or night designation. It can become day or night through the daybound and nightbound keyword abilities (see rule 702.145). Other effects can also make it day or night. Once it has become day or night, the game will have exactly one of those designations from that point forward.
    • 728.1a The phrases “day becomes night” and “night becomes day” refer to the game losing the first designation and gaining the second one.
  • 728.2. As the second part of the untap step, the game checks the previous turn to see if the game’s day/night designation should change. See rule 502, “Untap Step.”
    • 728.2a If it’s day and the previous turn’s active player didn’t cast any spells during that turn, it becomes night. Multiplayer games using the shared team turns option (see rule 805) use a modified rule: if it’s day and no player from the previous turn’s active team cast a spell during that turn, it becomes night.
    • 728.2b If it’s night, and previous turn’s active player cast two or more spells during the previous turn, it becomes day. Multiplayer games using the shared team turns option (see rule 805) use a modified rule: if it’s night and any player from the previous turn’s active team cast two or more spells during that turn, it becomes day.
    • 728.2c If it’s neither day nor night, this check doesn’t happen and it remains neither.

Rulings

• Once the game has a day or night designation, whether that designation changes each turn is generally determined by the number of spells the active player cast on the previous turn.
• Before a player untaps their permanents during the untap step, the game checks to see if the day/night designation should change.
• If it is day, and the active player of the previous turn cast no spells during their turn, it becomes night.
• If it is night, and the active player of the previous turn cast two or more spells during their turn, it becomes day.
• Double-faced permanents with daybound transform to their nightbound faces as it becomes night. Similarly, double-faced permanents with nightbound transform to their daybound faces as it becomes day. This happens immediately and is not a state-based action. It happens any time it becomes day or night, not just during the untap step.
• If you cast a spell with daybound during night, that spell will be front face up (that is, daybound face up) on the stack. However, it will enter the battlefield with its back face up (that is, with its nightbound face up). It won't enter with its daybound face up and then transform.
• If it is night, permanents with daybound that enter the battlefield without being cast will enter with their nightbound faces up.
• Permanents with daybound and nightbound can't transform via any means other than their daybound and nightbound abilities. Notably, older cards such as Moonmist that instruct a player to transform permanents don't affect permanents with daybound or nightbound.
• Once it has become day or become night, the game will have exactly one of those designations until the game is over. It can never be both day and night at the same time. Once it is day or night, the game can't return to being neither.
• The whole game is day or the whole game is night. It won't ever be day for one player and night for another.
• If it's neither day nor night, and a creature with daybound and a creature with nightbound somehow appear on the battlefield at the same time, it becomes day. The creature with nightbound will transform.

Clarifications

• If a nightbound permanent can't transform due to a card like Immerwolf, its nightbound face remains up even as it becomes day. If the effect preventing transformation ceases, it will immediately transform to "sync up" with the day/night cycle again. (The reverse applies to daybound permanents.)

Examples

Example 1

Tavern Ruffian
Creature — Human Warrior Werewolf
2/5
Daybound (If a player cast no spells during their own turn, it becomes night next turn.)

Example 2

Tavern Smasher
Creature — Werewolf
6/5
Nightbound (If a player cast at least two spells during their own turn, it becomes day next turn.)