Tragic Slip normally gives target creature -1/-1, but it gives that creature -13/-13 instead if a creature died this turn. This means that this can send just about any creature to the graveyard if a creature already died this turn. Note that Tragic Slip only checks whether a creature died this turn when it resolves, and not when you cast it.

For example, you control a Falkenrath Aristocrat and a Doomed Traveler, and your opponent casts Tragic Slip, targeting your Aristocrat. In response, you activate the Aristocrat’s ability, sacrificing the Doomed Traveler. When the ability resolves, your Aristocrat is indestructible and it gets a +1/+1 counter. This would normally prevent it from being sent to the graveyard, as Tragic Slip only gives -1/-1, but when Tragic Slip resolves, it checks to see if a creature died this turn. It notices that a Doomed Traveler was sent to the graveyard, so instead of -1/-1, it gives the creature -13/-13. It’s also important to understand that reducing a creature’s toughness to 0 will send it to the graveyard even if it is indestructible. This is because putting a creature in the graveyard for having 0 toughness is not destruction, which is what indestructibility prevents.

Today’s Rules Tip written by
Ronny Alvarado, Level 1 Judge from Houston, TX