Progression

Progression [CURRENT]

• XP per level (exponential): the XP to reach the next level is 100 × 1.15^(level−1) — every monster uses the same fixed curve, so it's 100 for L1→2, 115 for L2→3, ~405 for L10→11, ~1.6k for L20→21. On reaching the threshold, level +1, the carry-over resets, and HP/energy refill to the new level's max.
• Defeat a monster: 20 + level*10 XP and 4 + level*2 gold.
• Catch a monster: grants no XP — the reward is the captured monster itself (joined to team/vault, stabilized to a usable HP/energy). Only defeating a wild monster gives XP.
• Extract: +30 gold run-completion bonus.
• Gold: the only earned currency; persists across runs (per-defeat gold is kept even on a failed run — only the +30 extract bonus is forfeited). Spent on Base Upgrades, spirit-chain upgrades, and cosmetics. Designed curve (~20–50 runs to max upgrades): see docs/ECONOMY.md in the repo.
• Essence (premium): the paid currency (real money via Paddle) — not earned in runs, spendable on cosmetics only (never power). The old earned Spirit-Essence + chain crafting were removed; chain upgrades now cost gold.
• Team: 4 active slots. Vault: up to 100 (raised by the Deep Vault upgrade).
• Release (INV-T7): free an unwanted monster from the team or vault for a refund — level-scaled gold (no essence), the same amount a wild defeat of that monster's level grants (so a release is worth a consistent, non-free amount; scales with Prospector). You can never release your last monster, and releasing the only active one promotes a vault monster to keep ≥1 active. SP via the Inventory slot's Release action; MP via the roster inspect panel's Release button (server release handler, allowed only between rounds). Both use a two-step confirm. [CURRENT]
• Base Upgrades (account meta-progression): spend gold between runs on permanent upgrades that carry across every run — Prospector (+20%/lvl gold) and Deep Vault (+25/lvl vault capacity); 5 levels each, geometric cost. (Attunement was removed — essence is no longer earned.) Reached at the camp's Workshop station; engine in src/engine/upgrades.js (MP via the server buyUpgrade handler). [CURRENT]