Gideon's Sacrifice

Mana cost: {W}
Type: Instant
Set: Murders at Karlov Manor Commander #68 (common)
Price: $0.36 USD

Choose a creature or planeswalker you control. All damage that would be dealt this turn to you and permanents you control is dealt to the chosen permanent instead (if it's still on the battlefield).

Gideon's Sacrifice has 3 printings, first in War of the Spark (2019). EDHREC ranks it #5,217 among Commander cards. It appears most in Anti-Venom, Horrifying Healer decks (9,445 on EDHREC). 1 public deck on TCG runs it. It has 6 official rulings.

Legality

commander: legal
legacy: legal
vintage: legal
pauper: legal
modern: legal
pioneer: legal
standard: not legal
brawl: legal

Public decks that run Gideon's Sacrifice

Blame Game - Murders at Karlov Manor Commander, led by Nelly Borca, Impulsive Accuser

Commanders that run Gideon's Sacrifice most

Deck counts from EDHREC.

Anti-Venom, Horrifying Healer: 9,445 decks
Nelly Borca, Impulsive Accuser: 2,552 decks
Wayta, Trainer Prodigy: 2,376 decks
Jared Carthalion, True Heir: 2,250 decks
Kytheon, Hero of Akros // Gideon, Battle-Forged: 586 decks
Piru, the Volatile: 560 decks
The Sentry, Golden Guardian: 473 decks
Jennifer Walters // The Sensational She-Hulk: 380 decks

Often played with Gideon's Sacrifice

Cards that show up in the same decks on EDHREC.

Rulings

2019-05-03: If you control no creatures or planeswalkers as Gideon's Sacrifice resolves, nothing happens. The damage redirection effect won't be able to be applied to any damage events.
2019-05-03: More damage can be redirected to the chosen creature than it has toughness or to the chosen planeswalker than it has loyalty, as long as that damage is all dealt at once (like combat damage is) or is all dealt while a single spell or ability is resolving.
2019-05-03: If the chosen creature or planeswalker isn't on the battlefield or isn't a creature or planeswalker at the time damage would be dealt, the damage won't be redirected.
2019-05-03: Gideon's Sacrifice doesn't change the source of the damage or whether the damage is combat damage.
2019-05-03: Gideon's Sacrifice has no effect on damage already dealt earlier in the turn.
2019-05-03: If you cast more than one Gideon's Sacrifice in one turn, all damage that would be dealt at once to you and/or permanents you control is dealt to one of the chosen permanents of your choice. It's not dealt to all of them, and you can't split the damage between them. The next time damage would be dealt to you, you may choose a different one of those permanents to be dealt that damage.