MapCraft HQ

Battle Maps for Roll20 & Foundry VTT

A battle map only works online if its grid matches the table’s grid. Here is the pixel maths for Roll20 and Foundry VTT, a calculator to check your image before you upload, and step-by-step import instructions for maps from the MapCraft HQ generator.

Map size calculator

2,100 × 1,400 pximage size
150 × 100 ftarea in game
~2.6 MBrough PNG size (varies with detail)

Fine for both platforms.

Import into Roll20

  1. On the generator, set Pixels per square to 70 and press Download PNG. Note the size in squares shown under the map.
  2. In your Roll20 game, switch to the Map & Background layer.
  3. Drag the PNG onto the page (or add it from the Art Library).
  4. Right-click the image, choose Advanced → Set Dimensions, and enter the width and height in units (squares).
  5. Set the page size to match in Page Settings, and draw walls on the Dynamic Lighting layer if you use it.

Import into Foundry VTT

  1. Press Download .dd2vtt on the generator.
  2. In Foundry, install a Universal VTT importer module from the package browser (search “Universal Battlemap Importer”) and enable it in your world.
  3. Open the Scenes tab and use the importer’s button to load the .dd2vtt file. Walls, doors and light sources are created for you.
  4. No module? Download the PNG at 100 px per square, create a scene with it as the background and set Grid Size to 100.

Questions game masters ask

What size should a Roll20 map be?

Roll20 uses 70 pixels per grid square by default. A map that is 30 squares wide should be 2,100 pixels wide. Roll20 recommends keeping map images under about 10 MB; free accounts have a 10 MB upload limit per file.

What grid size does Foundry VTT use?

New Foundry scenes default to 100 pixels per grid square. Set the scene’s Grid Size to the pixels per square of your image, or import a .dd2vtt file, which sets it automatically.

What is a .dd2vtt file?

The Universal VTT format, first used by Dungeondraft. It is a JSON file holding the map image plus walls, doors and lights, so a map arrives in Foundry VTT, Fantasy Grounds Unity or Arkenforge with dynamic lighting already set up.

Can I use MapCraft maps in Owlbear Rodeo or Shard?

Yes. Download the PNG and set the grid in the tool to the map’s width and height in squares; every square is the same number of pixels, so it aligns exactly.

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