Ask where the measurement starts
When someone says “a circle of ten,” first ask whether they mean radius or diameter, and in which unit. In a geometric construction with a radius of ten units, the diameter is twenty. If they intended a diameter of ten, the radius is five. Drawing a circle does not resolve that ambiguity by itself.
DMGrid documents a distance ruler and templates, including a video of a circular template. The following exercise is tabletop preparation. It does not claim that the interface has a field called “radius” or automatically applies a spell’s rules.
Rehearse without inventing a game rule
On paper, choose a fictional exercise scale: one square equals one unit. Mark a centre and a point three squares horizontally away.
- The centre-to-point distance is three units: the chosen radius.
- The opposite edge is another three units beyond the centre.
- Edge to edge is six units: the diameter.
This is the example’s geometry, not a conversion between your campaign’s feet, metres or squares. Do not infer a digital map’s scale from a drawing’s physical centimetres.
If the group intended a diameter of three, this circle is too wide. Correct the interpretation before debating who is affected.
Separate scale, shape and resolution
When preparing a DMGrid scene, agree what the grid represents and what measurement you want to show. Use the published table-tool video and description as the reference. The Windows 0.1.9 beta includes a configurable grid, ruler and templates; this article does not establish an automatic rules engine.
Then consult the effect’s wording and agree how your rules handle boundaries, obstacles or partial squares. A template helps display an area; it does not make every nearby miniature a valid target. If the agreement changes, review the measurement and position again before continuing.
A preparation note might read: “Exercise scale: one square = one unit; radius three; diameter six; boundary inclusion unresolved.” This is an authored example, not a DMGrid-generated record.
Before choosing a tool, ask whether the measurement being discussed runs from centre to edge or edge to edge. Keep that answer with the agreed scale.
Do not copy another tabletop’s controls
Consulted on 24 October 2026, Foundry VTT distinguishes distance rulers and area templates, while Roll20 presents measurement tools and shapes. Their settings do not establish identical labels, shortcuts or rules in DMGrid.
Review the current beta and purchase terms. DMGrid is a licensed Windows purchase; its download is not a free demo. Before buying, check whether the documented tools fit your table and keep rules decisions with the group.