Preparing a Battle Map: Define Space

A battle map picture is just pixels until the app knows where the walls are. Define Space is where you tell it. Once the walls are in, light and sight stop at them, doors can be cut into them, and a player's token only sees the room it is standing in.

This is DM work. Players never see this screen, and the result saves with the encounter.

Where the flow starts

There are two ways in.

• Building an encounter. After monsters and a map are assigned, and before the Map Prep Workbench opens, a full-screen question asks "How is this map made?" Pick a method and the Workbench opens on its Floor bench ready to work. An encounter that already has a space skips the question. See chapter 12, Building Encounters, and chapter 13, The Map Prep Workbench.
• A map already in play. Open the map's settings sheet and find the "Contained space" row: Define space..., or Redefine... plus Clear once a space exists.

The three methods

The chooser offers three cards and pre-highlights the one it thinks fits. It never picks for you.

• Scan my drawing. A photograph of a map you drew yourself. Your pen strokes become the walls, and you touch up what the scan missed.
• Printed module page. A photographed page from a printed adventure. Tap inside a room and it selects itself.
• Trace the walls. Digital and painted map art, with no pen ink to read. The picture becomes a sheet you trace over.

Chose wrong? Tap Start over in the top bar, or the "Printed page" chip near the top left in printed method. Start over discards only work you have not committed.

Drawing walls

On a phone or tablet the tool row under the instruction line holds three cells: Pen, Shape, and Erase. Tapping the active cell opens its variants: Pen has Straight line and Freehand, Shape has Box and Circle, Erase has Freehand and Box. On a Mac or Windows machine all six are separate buttons: Line, Freehand, Box, Circle, Erase, and Box erase.

Straight lines join up when you start the next one on the end of the last, so four drags makes a room. Draw walls solid, leaving no gaps for doorways; doors get punched through later, in chapter 10, Doors and Lights.

Moving around never changes tools. Two fingers pan and zoom on a phone or tablet; on a Mac or Windows machine, scroll to zoom and drag with the middle mouse button to move. Tap the instruction line at the top for a fuller explanation of the current method.

Selecting the space

Walls are half the job. Now tell the app which side is indoors.

• Scan and trace methods: tap inside each room until it lights up. White is in the space, black is out. Tap a lit room again to take it back out. Press and hold a room to make it solid, or hold a solid nook to turn it into a room.
• Printed method: tap each room and corridor you want. A new room joins dark and unlit, tap again to have it lit from the start, and once more to remove it.

A printed-page tap spreads across the floor and stops hard at printed ink: wall lines, furniture, and label boxes all hold it in. Pen an open doorway shut first when two rooms must stay apart.

Two things interrupt the work.

• Amber dots mark places where your pen did not quite meet. Tap one and the app seals the gap for you.
• A leak. If the selection escapes through an opening wider than a doorway, it turns orange and the button reads "Seal the leak to continue". Draw a wall across the escape, then tap the area again.

Undo mark in the top bar takes back your last stroke. When the map looks right, tap Use this space. Inside the Map Prep Workbench there is no such button: leaving the Floor bench commits the work.

One banner is worth knowing. If most of your drawing touches the edge of the photo, the app says it was set aside as background, which usually means you handed the scanner finished map art. Take Trace instead; Keep edge ink keeps it anyway.

Coming back to it

Reopening Define Space on a map that already has one resumes from the walls you committed, so walls and lighting can go back and forth as often as you like. If the picture underneath has changed enough that the saved walls no longer sit on the drawing, the app says the saved walls drifted and asks you to seal the gaps before continuing, and Start over is always there for a clean slate.

What the walls do in play is chapter 28, Sight, Light, and Fog.