The Endless Delve

The post-Citadel endless descent — five kills per level, Echoing Crystals, and the re-entry toll.

The Endless Delve

The Endless Delve is a pure depth-check unlocked the first time you clear the Dark Citadel dungeon (defeat Theron). A portal opens in the burned village and drops you “into the Echo,” where every level holds five enemies and the fifth kill sends you one level deeper — forever, until you stop or die.

How the descent works

The run starts at a chosen start level (a fresh save’s first run begins at level 1, DELVE_START_LEVEL = 1).
Every level takes 5 kills (DELVE_KILLS_PER_LEVEL = 5); the combat overlay shows a five-segment bar under the delve label filling one segment per kill. Each descent raises the level by exactly +1 (DELVE_RANK_PER_LEVEL = 1), and the delve rank equals the level, so rank drives all enemy stat scaling with no cap.
Every descent refills your potion belt from your bag (best potions first). Nothing is conjured — the potions you bring are the run’s limit — but one belt no longer has to last the whole climb.
There is no boss and no “completion” — the run ends only when you stop or die.
The enemy roster, resistances, and theme are reused from the Dark Citadel region (the Delve lives inside the Echo).

Your deepest level ever reached is a persistent highscore (delveHighscore). When a run ends the summary lists start level, depth reached, time in the Delve and crystals earned with a per-hour rate; if you die offline, the offline report names the exact depth you fell at.

Dying in the Delve is free

The Delve is designed to end in death — you climb until the enemy outscales you — so the normal death economics do not apply inside it:

No gold loss. The usual 10% cut of your purse is waived (DELVE_DEATH_GOLD_LOSS_MULTIPLIER = 0). This matters because delve kills pay no gold at all, so the tax would have nothing to offset it — every run would be strictly gold-negative.
No durability loss. Your gear comes out of the Delve exactly as it went in (DELVE_DEATH_DURABILITY_LOSS_MULTIPLIER = 0).
No mode consequences. A delve death does not trigger the mediumcore wealth wipe or the hardcore save lockout (DELVE_DEATH_WAIVES_MODE_CONSEQUENCES = true), so the Delve is playable content in every mode.

The only thing a death costs is the run itself: the depth is gone and you are returned to the area you entered from. Getting back to the frontier is what the crystal skip fee below is for.

Enemy rarity cadence

Rarity is structured, not random, so depth is a clean read on build power:

Level pattern	Warden (the level’s last enemy)
Every 50th level (50, 100, 150, …)	Special
Every 10th level not a multiple of 50	Rare
Everything else	Common

Only the fifth enemy of such a level is the warden; the four before it are common. Special takes precedence over Rare where both would apply (50 is a multiple of 10). These breakpoints line up with the re-entry milestones and the crystal-tier steps below.

The only reward: Echoing Crystals

The Delve grants nothing but Echoing Crystals — no gold, no gear, no materials, no XP. Even its drops stay capped/normal; the Delve is not a combat tile, so Region Resonance never touches its rank, Magic Find, or material rates. All progression value is the crystals plus the highscore.

Crystals are what Region Resonance steps are paid in — 2,500 × the target level per step, 687,500 for the full five-region climb. That, on top of the Tier-5 craft fees, is what keeps the Delve worth running long after your highscore stops moving.

Every kill pays crystals for the level it happens on:

crystalsPerKill(level) = 5 × (floor(level / 50) + 1)

Level range	Crystals per kill	Per level (5 kills)
1–49	5	25
50–99	10	50
100–149	15	75
150–199	20	100
200–249	25	125

The skip fee (Echoing Crystals)

You cannot pick any start level — only level 1 plus each 10-level milestone up to your highscore. A highscore of 67 unlocks starts [1, 10, 20, 30, 40, 50, 60]. Starting at level 1 is always free. Starting at a milestone charges an Echoing Crystal fee worth half of what the skipped levels would have paid, rounded to tens:

skipFee(startLevel) = round₁₀( 0.5 × Σ 5 × crystalsPerKill(1 … startLevel−1) )

So level 10 → 110, level 50 → 610, level 100 → 1,860, level 150 → 3,740, level 200 → 6,240. The fee is paid up front to open the run.

Worked example — is skipping ahead worth it?

Say you want to farm the level-150-plus band. Two ways to reach level 200:

Start fresh at level 1 (free). You clear levels 1–199 to reach 200:
- 1–49: 49 levels × 25 = 1,225
- 50–99: 50 × 50 = 2,500
- 100–149: 50 × 75 = 3,750
- 150–199: 50 × 100 = 5,000
- Total ≈ 12,475 crystals, no fee.
Re-enter at level 150 (fee 3,740). You then clear levels 150–199 for 50 × 100 = 5,000 crystals to reach 200 — net +1,260 and 149 levels (745 kills) of fight time saved.