Indestructible

Indestructible is an evergreen keyword ability. Indestructible permanents can't be destroyed by rules or effects.

Description
Indestructible permanents can still be put into their owner's graveyard by other means, such as by the "legend rule", by being sacrificed or (in the case of creatures) having zero or less toughness. They can also be removed from the battlefield by being bounced or exiled for example.

History
The first card that conferred indestructibility was Consecrate Land in Alpha, followed by Guardian Beast in Arabian Nights, but no other cards followed (and no formal rules existed) until Darksteel. The word was originally used as a normal English descriptor rather than as a keyword. In this way, it was just an attribute that some permanents had. Enough players confused it with a keyword that R&D eventually decided to just make it one in Magic 2014.

Starting with Kaladesh, regeneration was retired. Instead, the phrase “gain indestructible until end of turn” came into being for new, but similar cards.

Indestructible is primary in white, secondary in black and green, and tertiary in blue and red. White, and to a lesser extent green, tend to have creatures that naturally have indestructible. Black and green, as the replacement for regeneration, often have activated abilities that grant indestructible until end of turn. White will at times use temporary indestructibility where it used to use protection.

Ikoria Commander introduced indestructible counters.

Removing indestructible
Removing indestructible is a newer, rarely-seen ability, primarily given to red due to its damage-based removal poorly translating to exile effects, acting as the successor to anti-regeneration text of the past. It has been printed on three spells so far, and separately, one green enchantment and one equipment have activated abilities that remove indestructible and hexproof.

Rulings

 * Damage accumulates on indestructible creatures, and that damage is removed during the cleanup step.
 * Lethal damage is defined as an amount of damage greater than or equal to a creature's toughness. Even though an indestructible creature isn't destroyed by lethal damage, that definition is still used for things like assigning trample damage.
 * If a creature with lethal damage on it stops being indestructible, it's destroyed the next time state-based actions are checked.
 * Being indestructible stops only effects that would destroy the permanent, including destruction due to lethal damage and destruction that doesn't allow regeneration. An indestructible permanent can be exiled, returned to a player's hand, put into a graveyard for having 0 or less toughness (via anything that gives -X/-X for example), or sacrificed.
 * You can use a regeneration effect on an indestructible permanent, but since that permanent can't be destroyed, the effect does not apply, unless it loses indestructibility before the end of the end step, then it would regenerate.
 * Planeswalkers with indestructible will still have loyalty counters removed from them as they are dealt damage. If a planeswalker with indestructible has no loyalty counters, it will still be put into its owner's graveyard, as the rule that does this doesn't destroy the planeswalker.

Magic 2014 updates:
 * In most cases, indestructible becoming a keyword doesn't represent a functional change. There are two exceptions:
 * Previously, if a permanent was made indestructible by a resolving spell or ability (such as Withstand Death), and then that permanent lost its abilities, it would still be indestructible. This was because indestructible wasn't an ability; it was just something true about the permanent. Now, the permanent will gain the ability indestructible, and it will lose this ability along with its other abilities.
 * Previously, if a group of permanents were made indestructible by a resolving spell or ability (such as creatures you control being affected by Rootborn Defenses), permanents that joined that group or entered the battlefield after that spell or ability resolved would also be indestructible. This was because the effect making the permanents indestructible wasn't changing any of those permanents’ characteristics. Now, a permanent that enters the battlefield or comes under your control after the spell or ability resolves won't have indestructible, as it wasn't under your control at the appropriate time to gain it.

Instant

 * Withstand Death

Enchantment

 * Indestructibility
 * Terra Eternal

Creature

 * Aegis Angel
 * Avacyn, Angel of Hope</c>
 * Archangel Avacyn</c>
 * Dauntless Escort</c>
 * Deathless Angel</c>
 * Slobad, Goblin Tinkerer</c>
 * Spearbreaker Behemoth</c>

Artifact

 * Darksteel Forge</c>
 * Darksteel Garrison</c>
 * Darksteel Plate</c>
 * Shield of Kaldra</c>
 * That Which Was Taken</c>

Planeswalker

 * Elspeth, Knight-Errant</c>
 * Vivien Reid</c>

Instant

 * Heroic Intervention</c>
 * Break of Day</c>
 * Mortal's Resolve</c>
 * <c>Lorehold Command</c>

Enchantment

 * <c>Shield of the Oversoul</c>
 * <c>Darksteel Mutation</c>

Creature

 * <c>Adanto Vanguard</c>
 * <c>Guardian Beast</c>
 * <c>Falkenrath Aristocrat</c>
 * <c>Knight Exemplar</c>
 * <c>Thornling</c>
 * <c>Timber Protector</c>

Artifact

 * <c>Eldrazi Monument</c>

Land

 * <c>Consecrate Land </c>

Creature

 * <c>Angelic Overseer</c>
 * <c>Athreos, God of Passage</c>
 * <c>Avacyn, Angel of Hope</c>
 * <c>Blightsteel Colossus</c>
 * <c>Bontu the Glorified</c>
 * <c>Brash Taunter</c>
 * <c>Colossus of Akros</c>
 * <c>Creepy Doll</c>
 * <c>Darksteel Colossus </c>
 * <c>Darksteel Gargoyle</c>
 * <c>Darksteel Juggernaut</c>
 * <c>Darksteel Myr</c>
 * <c>Darksteel Sentinel</c>
 * <c>Ephara, God of the Polis</c>
 * <c>Erebos, God of the Dead</c>
 * <c>Hazoret the Fervent</c>
 * <c>Heliod, God of the Sun</c>
 * <c>Iroas, God of Victory</c>
 * <c>Karametra, God of Harvests</c>
 * <c>Kefnet the mindful</c>
 * <c>Keranos, God of Storms</c>
 * <c>Kruphix, God of Horizons</c>
 * <c>Konda, Lord of Eiganjo</c>
 * <c>Manor Gargoyle</c>
 * <c>Mogis, God of Slaughter</c>
 * <c>Myojin of Cleansing Fire</c>
 * <c>Myojin of Infinite Rage</c>
 * <c>Myojin of Life's Web</c>
 * <c>Myojin of Night's Reach</c>
 * <c>Myojin of Seeing Winds</c>
 * <c>Nylea, God of the Hunt</c>
 * <c>Oketra the true</c>
 * <c>Ormendahl, Profane Prince</c>
 * <c>Pharika, God of Affliction</c>
 * <c>Phenax, God of Deception</c>
 * <c>Phylactery Lich</c>
 * <c>Predator Ooze</c>
 * <c>Purphoros, God of the Forge</c>
 * <c>Rhonas the Indomitable</c>
 * <c>Sapling of Colfenor</c>
 * <c>Sliver Hivelord</c>
 * <c>Spearbreaker Behemoth</c>
 * <c>Stuffy Doll</c>
 * <c>Tajic, Blade of the Legion</c>
 * <c>Toski, Bearer of Secrets</c>
 * <c>Thassa, God of the Sea</c>
 * <c>Transcendent Master</c>
 * <c>Ulamog, the Infinite Gyre</c>
 * <c>Xenagos, God of Revels</c>
 * <c>Zetalpa, Primal Dawn</c>

Artifact

 * <c>Darksteel Axe </c>
 * <c>Darksteel Brute </c>
 * <c>Darksteel Forge</c>
 * <c>Darksteel Ingot</c>
 * <c>Darksteel Pendant</c>
 * <c>Darksteel Plate</c>
 * <c>Darksteel Reactor</c>
 * <c>Darksteel Relic</c>
 * <c>Myr Matrix</c>
 * <c>Shield of Kaldra</c>

Land

 * <c>Darksteel Citadel</c>

Spells that remove Indestructible

 * <c>Bonds of Mortality</c>
 * <c>Burn from Within</c>
 * <c>Hour Of Devastation</c>
 * <c>Shadowspear</c>
 * <c>Soul Sear</c>