Foundry VTT Setup Guide

Foundry VTT Setup Guide

Quick Answer
How do you set up a battle map correctly in Foundry VTT?

Use the highest-quality gridless map file you have, create a Scene, set the background image, configure the grid before adding walls or lights, then trace the major boundaries that should block movement or vision. Foundry commonly works with maps at 70, 100, 140, or 200 pixels per square, so use the map documentation or Grid Configuration Tool instead of assuming one universal value. Finish by testing token vision, doors, measurements, fog, and the player view before the session starts.

You find the right dungeon map. The room layout fits the encounter, the file is high resolution, and a gridless version is included. You bring it into Foundry, place it as the Scene background, and then spend twenty minutes wondering why the tokens are sitting between squares.

That learning curve is real, but Foundry gives map-focused DMs a lot of control once the Scene is configured correctly. The core platform supports detailed grid settings, walls, token vision, fog exploration, tiles, lighting, and a large module ecosystem. The key is doing the setup in the right order.

This guide walks through the full process from map import to a player-tested Scene, with the mistakes that most often create misaligned grids, soft-looking maps, broken sightlines, and unnecessary performance problems.

Why is Foundry VTT so strong for battle maps?

The practical advantage is control. Foundry does not treat the map as one static image with a token layer on top. The Scene can combine a background, grid, walls, lights, sounds, tiles, fog exploration, token vision, and other placeable objects in one environment.

Self-Hosted Control
When self-hosting, your map library is stored on your own server rather than inside a SaaS account storage quota. Hosting-provider limits can still vary, so remote-server users should check their plan.
Walls + Vision
Walls can restrict movement, line of sight, and sound. Combined with token vision and fog exploration, they turn a static dungeon image into an explorable space.
Tiles + States
Tiles can add overlays, secret areas, overhead artwork, alternate room states, environmental objects, and other assets without rebuilding the Scene background.

How do you import a battle map into Foundry VTT?

Step 1
Upload the Map File

Use Foundry's File Picker to upload the map into an organized folder. For the Scene background, start with the highest-quality gridless version unless the map was specifically designed around a baked-in grid you intend to preserve.

Step 2
Create the Scene

Open the Scenes Directory, create a new Scene, and choose the uploaded file as the Background Image. Foundry detects the image dimensions automatically, although you can override the rendered dimensions if needed.

Step 3
Configure the Grid

Set the grid type and size before placing walls, lights, notes, or tiles. Foundry warns that changing grid size later can move or misalign those Scene elements.

Step 4
Set the Distance Scale

For standard D&D tactical maps, configure the grid scale so each square measures five feet. This drives ruler measurements and other distance-aware tools inside the Scene.

How do you calculate the correct grid size?

Foundry's Grid Size field is the number of pixels represented by one grid space. If the map documentation gives you the pixels-per-square value, use it. If it does not, divide the image dimensions by the known number of grid spaces or use the Grid Configuration Tool to align the map visually.

Grid Math
Image width ÷ grid columns

A 3080-pixel-wide map with 22 columns uses a 140-pixel grid. Foundry's own documentation lists 70, 100, 140, and 200 pixels per square as common map grid sizes. Use 140 when the source is actually built for 140, not because every high-resolution map is automatically 140.

For example, a 4096-pixel-wide map divided into 30 columns works out to about 136.5 pixels per square. Rather than pretending that file was built for 140, use the Grid Configuration Tool, background offsets, or rendered Scene dimensions to achieve clean alignment.

How do walls, token vision, and fog work together?

Foundry uses walls as virtual boundaries. Depending on their configuration, walls can restrict token movement, vision, and sound. Players do not need to see the wall segments themselves for those boundaries to affect what their tokens can perceive.

Trace Major Boundaries
Outline exterior walls, interior dividers, doors, and major opaque obstacles. You do not need to trace every decorative stone edge.
Enable Token Vision
When Token Vision is enabled, a player's Scene visibility depends on the vision of a token they control.
Use Fog Exploration Deliberately
Fog Exploration can remember previously explored areas per user, while current token vision controls what is visible right now.

The expensive part is wall tracing on complex dungeons. Keep the geometry as simple as the gameplay allows. A clean wall around the real sight boundary is usually better than tracing every tiny architectural irregularity and creating unnecessary processing work.

What image format should you use for Foundry maps?

Foundry currently supports AVIF, JPG, JPEG, PNG, SVG, and WebP image files. Its official media guide recommends WebP as the best general quality-to-size choice for Foundry use.

Format Foundry Use Tradeoff
WebP Strong default for Scene art and tiles Excellent quality-to-size ratio and transparency support
JPG / JPEG Efficient for large opaque backgrounds Smaller files, but compression can soften fine map detail
PNG Lossless maps, overlays, transparent assets Larger files can increase network transfer and load time

Higher resolution is useful until file weight starts working against the session. Remote players still need to receive the image over the network, so a huge lossless PNG can load more slowly than a visually comparable WebP. The right file is the one that stays readable at play zoom without creating unnecessary network overhead.

Which Foundry modules are useful for battle maps?

Modules are optional. Core Foundry already supports grids, walls, fog, lighting, tiles, and Scene management. The modules below are current examples that can expand or speed up map workflows, and each currently has a Foundry 14-compatible release. Always check compatibility before updating a live campaign.

Levels

Adds workflows for maps with multiple vertical levels. Useful for towers, balconies, stacked interiors, cliffs, and multi-floor structures where elevation is central to the encounter.

Monk's Wall Enhancement

Adds wall-editing quality-of-life tools such as splitting, joining, moving connected wall points, and freehand wall drawing.

FXMaster

Adds environmental particle and filter effects such as rain, fog, snow, color treatment, and underwater-style scene effects.

Sequencer

Adds visual-effect, sound, animation, and macro sequencing tools for DMs who want triggered scene effects or animated combat events.

From the Forge
Battle Maps Built for VTT Setup

Black Lantern Forge map packs include high-resolution gridded and gridless files with documented dimensions, so you can configure the Foundry Scene around the actual map instead of guessing at the grid.

Browse All Map Packs →

Why do Foundry Scenes look wrong after import?

Grid Misalignment
The Foundry grid does not match the source map's intended square size or background offset. Use the Grid Configuration Tool rather than nudging tokens around the problem.
Unexpected Padding
Scene padding creates playable border space around the background. Set it to zero if you specifically want the background to occupy the full Scene without extra staging space.
Overbuilt Walls + Lights
Too many tiny wall segments and unnecessary active effects can create more work than value. Build the boundaries and lighting the encounter actually needs.
Foundry rewards setup work done before game night. The players experience the polished Scene. They do not need to experience the configuration process.

How do you test the Scene before the session?

Foundry Scene Pre-Session Check
Grid squares align with the map
CHECK
One square measures the expected distance
CHECK
Doors block vision until opened
CHECK
No accidental gaps exist between wall segments
CHECK
Fog and token vision behave as intended
CHECK
Player view has been tested directly
CHECK

Use a test token with the same vision settings your players will use and walk through the Scene. Check corners, doorways, wall joints, dark spaces, and measurement distances.

Then inspect the Scene from a player-level login or another player perspective. GM view exposes information your players will never see. Testing the real player experience is the only reliable way to catch accidental reveals and broken sightlines before game night.

Frequently Asked Questions

Does Foundry VTT work with any battle map?

Yes, as long as the map uses a supported image format and can be configured as a Scene background. Foundry currently supports AVIF, JPG, JPEG, PNG, SVG, and WebP. For large Scene backgrounds, WebP is Foundry's recommended general format because it offers a strong quality-to-size ratio.

What is the correct pixels-per-square setting for Foundry battle maps?

There is no single universal setting. Foundry's documentation lists 70, 100, 140, and 200 pixels per square as common values. Check the map documentation first. If the value is not provided, divide the image dimensions by the known square count or use the Grid Configuration Tool to align it visually.

How do I set up Foundry walls without spending hours tracing?

Trace the major boundaries that should affect movement or vision instead of every decorative edge. For a large dungeon, focus on exterior walls, room dividers, doors, and important opaque obstacles. Optional modules such as Monk's Wall Enhancement can add wall-editing tools that speed up the process.

Should I use gridded or gridless maps in Foundry VTT?

Gridless is usually the most flexible choice because Foundry can apply its own grid at the exact Scene scale. A baked-in grid can still work, but it requires accurate alignment between the source artwork and Foundry's grid. Keep gridded files for physical play or when you specifically want the grid built into the art.

How do remote players connect to a Foundry game?

Foundry can be self-hosted, which may require network configuration such as port forwarding, or it can be run through a third-party Foundry hosting provider. In either case, players connect through a browser and do not need to purchase their own Foundry license.

Can I reuse the same Foundry Scene in another world?

Yes. Foundry supports Scene data export and import, and compendium workflows can also be used to move reusable content between worlds. That makes careful wall and lighting setup more valuable when the same encounter location may appear in multiple campaigns.

How much does Foundry VTT cost?

Foundry currently sells an individual software license for $50 USD. The license is perpetual and includes future core software updates. One license can host a game server for players, and the players do not need to purchase their own copies to connect.

From the Forge
Give Foundry a Map Worth Building Around

High-resolution map packs with documented dimensions, gridded and gridless versions, and encounter spaces designed for walls, lighting, tokens, and real tactical play.

Shop Battle Map Packs →

Sources

Foundry VTT Scenes and Grid Configuration
Foundry VTT Walls
Foundry VTT Media Optimization Guide
Foundry VTT Tiles
Foundry VTT Software License