Hexproof

Hexproof is an evergreen keyword ability that prevents a permanent or player from being the target of spells or abilities played by opponents.

Description
Hexproof was first introduced in Portal Three Kingdoms on two green creatures, but was only keyworded in Duels of the Planeswalkers 2012. It functions as onesided Shroud: a permanent with hexproof can't be the target of spells or abilities its controller's opponents control, though it can be targeted by its controller's spells or abilities. In a multiplayer scenario, a permanent with hexproof can also be targeted by its controller's teammates' spells or abilities. Players can also be granted hexproof.

Hexproof debuted in Duels of the Planeswalkers 2012 and appears in subsequent card sets, including Commander and the Magic 2012 Core Set. All cards printed prior to these sets' release that have text that exactly matches what hexproof does have received updated official wordings with the new keyword. Since Magic 2012, Hexproof has been considered an "evergreen" ability, largely replacing shroud. However, R&D started to consider that hexproof was problematic in cases, and experimented with conditional hexproof; this resulted in a mechanic that was originally referred to as "frost armor" and is now known as ward.

Hexproof is primary in blue. Blue both has the most creatures with hexproof out of all colors and often grants it to creatures as a pseudo-counterspell. Green is secondary: it tends to get hexproof on larger creatures without evasion. White is tertiary: it gets hexproof infrequently, sometimes on players, in ways that feel like it's protecting the thing.

Ikoria: Lair of Behemoths introduced hexproof counters.

Hexproof from
Dominaria introduced "hexproof from [ quality]" as a variant of the hexproof ability, and mirroring "protection from [quality]". For example, "hexproof from black" means "this permanent can't be the target of black spells your opponents control or abilities of black sources your opponents control."

Rulings

 * A permanent with hexproof can still be the target of spells or abilities controlled by that permanent's controller or that player's teammates. The same is true for a player with hexproof.
 * Aura spells target a permanent or player. You can't cast an Aura spell targeting an opponent's permanent with hexproof.
 * Auras on the battlefield don't target anything. Granting hexproof to a permanent or player doesn't cause opponents' Auras to become unattached.
 * A card that has ‘hexproof’ is still affected by board wipes that affect both players.

Enchantments that grant just Hexproof
One player (yourself)
 * Imperial Mask
 * Leyline of Sanctity

Creatures you control
 * Asceticism
 * Archetype of Endurance (creatures you control, remove it from creatures your opponents control)

Permanents (besides itself) you control
 * Privileged Position

Trivia

 * This mechanic was colloquially referred to as "Troll Shroud" before the introduction of the keyword, in reference to Troll Ascetic, one of the first and most popular cards with hexproof.
 * Wizards of the Coast has stated that with the introduction of Hexproof, there is no intent to print any new cards with shroud.
 * Glaring Spotlight and Detection Tower make it possible that creatures your opponents control with hexproof can be the targets of spells and abilities you control as though they didn't have hexproof.
 * Shadowspear</c>'s second ability can temporary remove hexproof from permanents under opponents' control.