MTG Undercity Dungeon — Hex pyramid prop

A physical play prop for the **Undercity** dungeon from MTG's

*Commander Legends: Battle for Baldur's Gate* (token 020/020). When

your deck wants to *venture into the dungeon*, this is the board

your pin walks across.

Nine hexagonal rooms in a 1-2-3-2-1 pyramid layout, all twelve

canonical dungeon connections cut as door gaps in the walls, each

room engraved with **its glyph and its effect text** (not the

flavour name — what triggers when you venture there is what you

need to read at the table). Plus a fitted player pin and four

parking slots in the UNDERCITY title banner so a 4-player table can

keep their unused pins on the board.

## Layout

```

                  ⌂  Secret Entrance        (find basic)

                 /                \

       ♨  Forge                    ◯  Lost Well   (scry 2)

   (+1/+1 ×2)         /        \

       /                                       \

  ✕ Trap!  ⚔  Arena                  ◆  Stash

 (-5 life) (goad)                  (treasure)

       \        /  \                /

       ✎ Archives    ☠  Catacombs

       (draw 1)      (4/1 menace)

                  \        /

                   ♛  Throne of the Dead Three

                   (top 10: 3/3 hex creature)

```

The 12 doors follow MTG's dungeon-graph edges. The 4 same-row pairs

that **aren't** connected in the rules (Forge↔Lost Well, Trap↔Arena,

Arena↔Stash, Archives↔Catacombs) stay walled — no door — so the

prop reproduces the actual dungeon, not just the visual.

## What's in the bundle

- `undercity_dungeon_combined.stl` — the dungeon board: body + labels

  in one ASCII STL with **two named solids** in a single coordinate

  frame.

- `undercity_dungeon_pin.stl` — one player pin (cone with a peg base).

- `undercity_dungeon.scad` — full parametric source.

## How to print (board, two-colour AMS)

The board is a coordinate-locked two-colour print: a dark stone body

with the glyphs, room names, brick mortar and title plaque all

engraved as recesses, then refilled in a contrasting colour

(traditionally gold).

1. Bambu Studio → **Import** `undercity_dungeon_combined.stl`.

2. Right-click the imported object → **"Split to Parts"**.

3. Sub-parts named `body` and `labels` appear, locked at exact

   original coordinates.

4. Assign **filament A (dark / structural)** to `body`. Assign

   **filament B (gold / accent)** to `labels`. Slice. Print.

> Why combined STL with named solids? Bambu's "Add Part" workflow

> rearranges coordinates — labels would land off-centre from the

> body. Single ASCII STL with two named solids + Split-to-Parts

> preserves alignment exactly. (Background in the source repo's

> CLAUDE.md "Multi-Color (Bambu Studio AMS)".)

For non-Bambu slicers that respect coordinates on import, you can

re-render `body.stl` and `labels.stl` separately from the .scad

source — drop them onto the bed in two passes and the second one

will land centred on the first.

## How to print (player pins)

Print `undercity_dungeon_pin.stl` **once per player** in a different

filament colour each time. Cone-shaped (Ø9 × 9 mm body) with a

Ø3.4 × 5 mm peg base. The peg slips into a Ø3.6 × 4 mm hole in

each room — 0.2 mm radial slip fit, snug but pulls out cleanly.

Each room has **two peg holes** so two players can occupy the same

room at the same time without fighting for the slot. Park unused

pins in the **4 parking holes** at the top of the UNDERCITY banner.

## How to play

1. At game start, slot every player's pin into one of the 4 parking

   holes along the title banner.

2. When a player **ventures into the dungeon** for the first time,

   they pull their pin from parking and put it in the **Secret

   Entrance**.

3. On each subsequent venture, they move their pin to a connected

   room through one of the visible doors.

4. The **Throne of the Dead Three** is the last stop — its effect

   resolves and the dungeon completes.

The bottom face of the centre column carries an engraved **"Take

Initiative"** inscription — the other Undercity-related MTG

mechanic. Visible when you flip the prop.

## Print settings

- Bambu Lab P2S or any 0.4 mm FDM

- 0.2 mm layer height, 3 walls, 15 % infill

- PLA Basic — works perfectly. Tested with dark base + gold accent.

- **No supports.** Every overhang is ≤ 45°.

- Board prints flat on the bed, label face up.

- Pins print flat on their base, peg pointing up.

## Source

The included `.scad` exposes hex circumradius, wall height, label

recess depth, glyph size, font, and all 9 rooms as parametric

data. Easy to retune for a different aesthetic, a different game's

dungeon, or a denser hex grid.

Fan content for **Magic: The Gathering** — not affiliated with

Wizards of the Coast.