Cartosmith

A battle map built for the DM.

Cartosmith is a tabletop battle map program. Run the whole encounter, with initiative, movement, conditions, doors and spell effects, all on one DM screen.

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The Cartosmith DM screen mid-encounter in a steampunk tower: a lit battle map in the centre, floor tools on the left, and an initiative list of friendly and hostile creatures on the right.
The DM Prep overlay on a castle treasury map. Doors and chests carry colored markers showing which are trapped, locked, safe or ordinary.
Castle Nightspire, Treasury and Hidden Vault: 6 trapped, 6 locked, 5 safe, 4 ordinary.

Prep every trap and secret.

Mix ordinary, locked, safe and trapped doors and chests. DM Prep keeps the differences visible at a glance, and the overlay is for the DM only.

  • Armed trap
  • Door
  • Chest or interactable
  • Safe state

Whole buildings, floor by floor.

Link stairs and passages between floors. See your party and enemies across the whole tower at a glance.

  • Friendly
  • Hostile
  • Active turn
Cartosmith showing the ground floor of a five-floor tower, with the building overview on the left and the initiative list on the right. The DM building overview: five stacked floor outlines, from The Threshold Concourse up to The Weave Crown, with creature markers on each floor.
The Lumen Spire, five floors with two creatures on each floor. The building overview on the right is for the DM.

Fog that knows what they can see.

One encounter. Two heroes across a maze of angled rooms, windows, doors and hallways.

The complete encounter on a honeycomb of hexagonal clockwork rooms, as the DM sees it, with every room and token visible.
DM view. The complete encounter.
Player 1's view: only the hexagonal room Mira stands in and a slice of the next room are visible. Everything else is dark.
Player 1, Mira. Western apiary.
Player 2's view: Rowan's room and the lines of sight through its doors and windows are visible. Everything else is dark.
Player 2, Rowan. Eastern apiary.

Brassgate, Clockwork Apiary: 24 windows and 33 doors. Same floor and token positions in every view.

Spells that look like spells.

Fire, ice, lightning, vines and auras. Eight effects, with a hero's aura inside the cold cone.

Eight spell templates on a grid: Fireball, Cone of Cold, Spirit Guardians, Wall of Fire, Entangle, Lightning Bolt, Darkness and Web, each drawn with its own texture and labeled with its size.
Real spell templates rendered in Cartosmith, on a 5 ft grid, shown at their in-app size.
Three overlapping Cartosmith windows in different themes: a dark red-tinted theme, a deep blue theme and a light parchment theme.

Make it yours.

Five themes, from Ravenloft to Parchment, and a High Contrast option for easy reading.

Be there when Cartosmith opens.

Leave your email and we'll let you know when it's ready.