M+10 vs M+15 in Midnight Season 2 — When to Upgrade Your Weekly Key

For most Mythic+ players the weekly question isn't “what dungeon should I run?” — it's how high should I push my key. In Midnight Season 2that question has a different answer than it did last season, and it's the kind of difference that quietly wastes a lot of people's evenings.

Here it is up front: gear caps at M+10. A timed +15 puts exactly the same item level in your vault as a timed +10 — Myth 318, with a Hero 311 end-of-dungeon drop. But crests keep scaling to M+12, and crests are what upgrade the gear you already own. That's the part last season didn't have.

What actually changes at +10 vs +12 vs +15

Vault item level: +10 → 318 · +12 → 318 · +15 → 318 · no difference
End-of-dungeon drop: +10 → 311 · +15 → 311 · no difference
Crests: +10 → 12 Myth crests · +12 → 16 Myth crests · +15 → same as +12 · this is the new reason to push to 12
Rating per timed run: +10 → ~320 · +15 → ~410 · the only reason to go past 12
Dungeon teleports: unlocked by timing a +10 or higher — same level that maxes your gear
ETA: +10 → ~25 min · +15 → ~30 min

The vault math

Your weekly Great Vault gives three Mythic+ choices, unlocked by your 1st, 4th and 8th highest timed keys of the week. Because the reward caps at +10:

1 timed +10 → first vault slot at Myth 318 (the season maximum)
4 timed +10s → second slot, same item level
8 timed +10s → all three slots at Myth 318 — a fully maxed vault
8 timed +20s → identical vault, considerably more risk and cost

So if item level is the only thing you care about, eight keys at +10 is still the answer, and the Full Vault bundle is the cheapest way to get there. But item level isn't the only thing you should care about this season.

The crest argument for +12

Drops set your starting item level. Crests set your ceiling — they're what you spend to push a piece up its upgrade track. A +12 pays 16 Myth crests against a +10's 12 Myth crests, for gear that is otherwise identical.

Run eight keys a week and that difference compounds into a meaningful number of extra upgrades over a season. This is the single biggest change from last season, when +11 and +12 paid nothing whatsoever beyond rating and the standard advice was to stop at +10. That advice is now leaving currency on the table.

Above +12, everything flattens: same gear, same crests, more risk. M+12 is the most rewarding key in the game, and we run it at $11.

So why push past +12 at all?

Two legitimate reasons, neither of which is loot:

Milestone rewards. Rating unlocks the season's cosmetics — 2,000 for Breath of Blight, 3,000 for Breath of Ruin. See the full rewards table.
Leaderboard placement. 3,000 is the highest fixed gate in Midnight Season 2. Past it, the only remaining reward is top 0.1% of region — "the Venomous Hero" regional title — and that cutoff only moves if you push.

The deplete risk gap

+10 is the “floor” tier — affixes are soft, the timer is generous, and depletes are rare even for pugs. Most players reading this can pug 8× +10 in an evening with a high timer rate.

+15 is where pugs start failing meaningfully. A depleted +15 costs you the run and drops the keystone to +14 — 35 minutes spent for zero rating, and now you have to time +14 before you can attempt +15 again. Since both gear and crests are already capped, a failed +15 loses you nothing in rewards but everything in time.

Resilient at +16 exists to break that cycle — once you time all 8 dungeons at +16, your keystone floor locks at 16 for the rest of the season.

When to upgrade: a decision framework

Stay at +10 if:

You want a guaranteed maxed vault with the lowest possible deplete risk
You play 4 hours/week or less
You're gearing a fresh character or an alt, and teleports are the priority

Push to +12 if:

You want the best rewards available — it is strictly the best key in the game
You're upgrade-capped rather than drop-capped, which most geared characters are by mid-season

Go past +12 only if:

You're climbing toward Keystone Legend at 3,000
You have a static group with a proven timer rate at that level

Cost comparison: DIY vs boost

Pugging a single +15 dungeon successfully (multiple group rebuilds counted):

Time investment: 60–120 minutes including failed groups
Real cost: 2–3 hours of a weekend or weeknight

Buying a single timed +15 from us:

Price: $28 USD (published catalog rate — /mythic-plus/15; price-match on top if you find lower)
Time investment: ~30 min run + 5 min Discord booking
Success rate: 100% timed or re-run free

For a maxed vault, the 8× +10 bundle at $60 is the better buy — single-block scheduling, one Discord conversation, and it fills every vault slot at the season ceiling.

FAQ

Should I time +15 once or +10 eight times?

For gear: eight +10s, without question — that maxes all three vault slots, and a +15 adds nothing on top. For rewards overall, eight +12s beats both, because the gear is identical and the crests are better. A +15 is a rating purchase.

Does timing +15 give me Keystone Master?

No — and this trips up a lot of returning players. Keystone Master is a 2,000-rating achievement, not a “time a +15” achievement. It rewards Breath of Blight. See the Keystone Master package.

What about +11, +12, +13, +14 — are those worth running?

+11 and +12 genuinely are, and this reverses last season's advice: their vault and end-of-dungeon rewards match +10, but their crest payouts don't — +12 pays 16 Myth crests against 12 Myth crests at the cap. +13 and +14 are the ones that add nothing but rating.