[RPG] How to map a 15′ cone to a 1″ grid

area-of-effectbattle-mapdnd-5espells

I've been playing 5e for a while now, and mercifully this hasn't come up yet, but it's definitely on it's way.

When a caster casts burning hands, how is that properly mapped onto a standard 1" battle mat? The easy response is a 3×3 square, and that's the method I've told myself I'm going to use. But is there a better template?

The 3×3 grid works great if the caster casts on a corner, it matches the description of a cone perfectly (each square is 5', 10, 15' away for the purposes of grid math). However, when a caster casts the spell in a cardinal direction (N/S/W/E), that math breaks down. now a second or even third square is adjacent with a 3×3 square and the spell description has fall apart.

What are the appropriate grid shapes for a 15' cone?

Best Answer

Here are some examples of the areas affected by a 15-foot cone cast at different angles.

The point of origin is shown at an intersection between squares (as recommended in the DMG), and also centered on the side of the square for attacks in a cardinal direction (which is more intuitive).

Here are all the squares that are touched by the cone:

15-foot cone area of effect

15-foot cone area of effect, with point of origin in line with center of square

Here are all the squares that are 50% or more covered:

15-foot cone area of effect (50% or more covered)

15-foot cone area of effect (50% or more covered), with point of origin in line with center of square

This is probably as close as you can get to the standardized shapes of previous editions.

A more generous interpretation in keeping with the spirit of the rules would be to say that the cone hits any creature whose circular base is overlapped:

15-foot cone area of effect with circular bases

15-foot cone area of effect with cirular bases, with point of origin in line with center of square