A cone starts at a point and opens in one direction
Before counting targets in a cone, establish its origin, direction and the length specified by the effect. Do not replace it with a circle reaching the same distance: distance from the origin alone does not establish inclusion in a directed area.
The DMGrid presentation documents circle, cone and square templates for displaying areas on the board. This guide uses the cone definition in the free D&D 2024 rules. The template displays a proposal; this is not a claim of automatic adjudication of every rule.
Read length and width together
Under that definition, a cone extends from its origin in the chosen direction. Its width at a point along its length equals that point’s distance from the origin. The particular effect specifies maximum length.
Geometric preparation example: an effect creates a 15-foot cone. At 5 feet from the origin it is 5 feet wide; at 10 it is 10 wide; at 15 it is 15 wide. Those dimensions do not describe a 15-foot radius surrounding the creator.
They are not an automatically affected square list: apply your system and table’s grid-placement method. We are not inventing a spell with this range. Read the actual effect being used.
Prepare the template before resolving the roll
When using DMGrid’s board, bring these checks to the table:
- Locate the effect’s origin according to its description.
- Choose the direction and represent the cone with the appropriate tool.
- Check map scale and the length the effect requires.
- Review proposed targets and relevant resolution conditions with the group.
- Then apply the actual effect’s rolls and consequences.
These are preparation steps, not button names or evidence of automatic creature selection. After rotating the cone, check its orientation before resolving it. A target’s distance from the origin can stay unchanged while its inclusion in the chosen direction changes.
Retain the other area rules
The 2024 glossary also discusses origins and area obstructions. A drawing crossing a door does not by itself establish that an effect passes through a wall. Review shape, origin and cover alongside the effect’s description.
Foundry documents its own template tools; its settings do not establish DMGrid controls or values. Check the program you use rather than copying another program’s shortcuts.
DMGrid is a paid Windows beta for local campaigns. Review current scope and licensing before buying. In your next scene, establish the cone’s direction before deciding whom it reaches.