#Magic Vault 5×3

A 5-reel × 3-row, 10-payline fantasy-vault slot. Its Hold & Win feature is the approved hold_and_win/v1 mechanic, reused unchanged; everything else — symbols, reels, paytable, trigger distribution and whole-game RTP — belongs to this game.

draft-v0.1 — DEV ONLY. NOT FOR PRODUCTION. NOT FOR CERTIFICATION. Not frozen. Published and enabled only on DEV for operator demo, demo mode and demo wallet. Internal tests, simulations and DEV smoke are not external certification.

Draft math APPROVED 2026-08-10. The version stays in draft state. Approving the Draft numbers is not a freeze, not a Final and not a production release: no final-* version exists, and stage/production remain unavailable.

The canonical config is not duplicated here. This workspace records its path, the backend Git identity and the SHA-256 above, and every number below is reproducible from them.

The approved Draft is currently playable through the DEV API for demo sessions only. This is an integration environment, not a production release or a change of lifecycle status.

#Design gate

DESIGN approved 2026-08-10, scope bound to docs/superpowers/specs/2026-08-10-magic-vault-5x3-design.md. Implementation follows docs/superpowers/plans/2026-08-10-magic-vault-5x3-draft-math.md.

#Game at a glance

Grid:            5 reels × 3 rows
Evaluation:      10 fixed paylines, left to right, beginning on reel 1
Symbols:         WILD, COIN, H1-H4, L1-L4   (there is no BONUS symbol)
Wild:            substitutes for H1-H4 and L1-L4; never makes a COIN line pay
Coin:            no line payout at any count; its value lives inside the feature
Trigger:         6 or more visible COIN
Carry-over:      the triggering COIN cells ARE the initial locked cells, in place
Feature grid:    5 columns × 3 rows (15 cells), cell index = column*3 + row
Initial respins: 3
Landing chance:  43,000 PPM (4.3%) per empty cell
Respin reset:    any newly landed prize resets remaining respins to 3
Miss-only step:  remaining respins decrement by 1
Termination:     respins reach 0, or all 15 cells locked
Ordinary award:  sum of locked prizes, capped once at 500× total bet
Full grid:       exactly Grand 500× total bet, REPLACING the sum
Additional bet:  none

#Draft results

Exact and simulated figures are kept in separate columns throughout. Nothing sampled is labelled exact.

Total RTP = exact base RTP + exact P(trigger) × estimated E[award | trigger].

Known Draft deviation from the design brief. The design's 55.44% base target assumed Magic Vault would inherit the reference harness's 32.4461× conditional mean. It does not: the same mechanic entered from Magic Vault's own distribution of initial locked cells measures 31.6252×. Re-deriving 0.96 − P(trigger) × measured mean gives 55.9962%, and the base paytable was retuned to it. No Hold & Win parameter was changed. See changelog.md and evidence/simulation/draft-v0.1.md.

#Art

Existing assets only, from /Users/admin/frontmvp/template_symbols. No new art is required.

Unused in Draft v0.1: symbol_bonus.png, symbol_scatter.png, symbol_mystery.png, fs-background.png.

#Not in Draft v0.1

Free spins, feature buy, Mystery, Scatter, collectors, extra multipliers, additional wagers, gamble, any change to hold_and_win/v1, new art, production/stage deployment, bundled frontend, Final/Freeze/Handoff.