Rules: Does Indestructible Stop Exile? What Indestructible Actually Prevents

Short answer first, then the reasoning — that is how rules questions deserve to be answered, because you usually need this ruling in the middle of a game.

The answer

No — and the distinction wins and loses real games. Indestructible means a permanent cannot be destroyed: destroy effects fail against it, and lethal damage marked on it does not destroy it. Exile is not destruction. An exile effect simply moves the permanent to the exile zone, and indestructible has nothing to say about it. The same logic covers the other routes around indestructible: sacrificing the permanent (its controller chooses and sacrifices it — again, not destruction), and effects that reduce its toughness to zero or less with -X/-X, because a creature with toughness 0 or less is put into the graveyard by state-based actions rather than destroyed. What indestructible genuinely stops is the everyday traffic of Commander: destroy-based board wipes, destroy-based removal, and combat or burn damage that would otherwise be lethal.

The cards involved, on their real text

Avacyn, Angel of Hope (mana cost {5}{W}{W}{W}; Legendary Creature — Angel; 8/8; rarity: mythic; most recent printing listed by Scryfall: Innistrad Remastered): Flying, vigilance, indestructible
Other permanents you control have indestructible.

Path to Exile (mana cost {W}; Instant; rarity: uncommon; most recent printing listed by Scryfall: Reality Fracture Commander): Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Build and check your list with the MTGBrew card database, and browse every card mentioned here in the MTGBrew Learn guides on MTGBrew.

If this topic is on your bench, keep going with Kaalia of the Vast Commander Guide: How the Deck Actually Wins — it covers the neighbouring decisions from a different angle, and the two pieces together give you a fuller picture than either one alone.

Keep reading

Keep reading: Kaalia of the Vast Commander Guide: How the Deck Actually Wins and Mana Base Guide: Five-Color Mana Bases — Making Any Color Without Falling Apart.

Why this keeps coming up

Most rules confusion is really wording confusion: two game words that sound similar — destroy and exile, damage and life loss, target and choose — mean different things, and the difference is deliberate. When a ruling surprises you, read the exact words on the cards involved, in the order a judge would. Nine times out of ten, the text already contains the answer, which is why MTGBrew's guides quote oracle text instead of paraphrasing it from memory.