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

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.

For non-Bambu slicers that respect coordinates on import, you can re-render the body and the labels as separate STLs 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.