Mod Grid — Cell Unlock System
Defines the cell pricing, unlock sequence, and addressing scheme for the account-wide Mod Grid. The grid is a 4×4 board (16 cells). Some cells are free; the rest are bought one at a time with credits in a fixed order. This page is the system of record for those costs and that order — individual mod templates live on their own pages.
Grid coordinates
Cells are addressed by (col, row) with both axes zero-indexed (0..3). The persistence key is the literal string "col,row". Out-of-range coordinates throw at lookup time — there is no silent clamp.
Display labels used in dev notes follow a row-letter / column-number convention (row 0 = A, column 0 = 1). The numeric (col, row) form is authoritative.
Cell pricing tiers
Every cell belongs to exactly one of three price tiers, determined by its position on the board.
| Tier | Cost (credits) | Where | Cell count |
|---|---|---|---|
| Free | 0 | Upper-left 2×2 block (col ≤ 1 and row ≤ 1) | 4 |
| Inner | 1,000 | Remaining cells inside the upper-left 3×3 (col ≤ 2 and row ≤ 2, minus the free block) | 5 |
| Outer | 10,000 | Outer rim — col 3 or row 3 | 7 |
Total spend to fully unlock all 16 cells: 75,000 credits (5 × 1,000 + 7 × 10,000).
Free zone
The upper-left 2×2 (cells (0,0), (1,0), (0,1), (1,1)) is permanently unlocked. New accounts start with these four cells available; no purchase or progression gate sits in front of them.
Unlock sequence
Locked cells cannot be purchased in arbitrary order. The player can only ever buy the next cell in a fixed sequence; every later locked cell renders as hidden until its turn. All five Inner-tier cells must be purchased before any Outer-tier cell becomes available.
| Order | Cell (col, row) | Tier | Cost |
|---|---|---|---|
| 1 | (2, 0) | Inner | 1,000 |
| 2 | (2, 1) | Inner | 1,000 |
| 3 | (2, 2) | Inner | 1,000 |
| 4 | (1, 2) | Inner | 1,000 |
| 5 | (0, 2) | Inner | 1,000 |
| 6 | (3, 0) | Outer | 10,000 |
| 7 | (3, 1) | Outer | 10,000 |
| 8 | (3, 2) | Outer | 10,000 |
| 9 | (3, 3) | Outer | 10,000 |
| 10 | (2, 3) | Outer | 10,000 |
| 11 | (1, 3) | Outer | 10,000 |
| 12 | (0, 3) | Outer | 10,000 |
The Inner-tier path expands the active footprint to a full 3×3, then the Outer-tier path walks the right edge top-to-bottom and the bottom edge right-to-left.
Persistence
Purchased cells are tracked as a set of "col,row" strings. The “what can I buy next” query walks the unlock sequence and returns the first entry not present in the purchased set. When every cell is in the set, the query returns null (grid fully unlocked).
Dev affordances
A helper that emits all 16 cell keys exists for “unlock everything” debug flows. It iterates rows then columns and is intended for dev tools only.
EXTRACT-CANDIDATE flags
- EXTRACT-CANDIDATE — Mod Grid concept page. Pricing + sequence here are the unlock half of the grid system; the placement/rotation/merge half lives in
_types.tsand is summarized on the Mods overview. A combined “Mod Grid” concept page covering free zone, unlock order, placement rules, and merge mechanics would let per-mod pages link to a single canonical reference. - EXTRACT-CANDIDATE — Economy: credit sinks table. The 75,000-credit full-unlock figure belongs in a roll-up of all credit sinks (grid expansion, ship purchases, etc.) on the economy page.
Summary
grid-unlock.ts is not a mod template — it is the unlock-pricing module for the 4×4 account-wide Mod Grid. Four upper-left cells are free, the remaining twelve are bought one at a time along a fixed twelve-step sequence: five Inner cells at 1,000 credits each (completing the 3×3), then seven Outer cells at 10,000 each (filling the rim). Total full-unlock cost is 75,000 credits. Cells are persisted as "col,row" strings; the “next purchasable” lookup walks the sequence and returns the first unpurchased entry.