Rain in the real world and GURPS MAGIC

[maximara]

Originally Posted by hal

See page 13 of GURPS MAGIC for 4e, which discusses just that above, in its Box. The money phrase is

"Represent Area spells on a battle map as follows:

The area of effect of a spell cast over a one-yard radius is a single hex. The area of effect of a spell cast over a two-yard radius is a central hex and all adjacent hexes. The area of effect of a spell cast over a three yard radius is a central two-yard area of effect plus the ring of hexes adjacent to that."

This is exactly what is on B239:

"The area of effect of a spell cast over a one-yard radius is a single hex. The area of effect of a spell cast over a two-yard radius is a central hex and all adjacent hexes. The area of effect of a spell cast over a three-yard radius is a central two-yard area of effect plus the ring of hexes adjacent to that." (sic)

None of this changes the fact that the area covered depends on how the circle is placed on the hexagon.

Bill Stoddard seems to be saying the circle is inside the hexagon ie A= 2 * √(3) * R^2

But the way both Magic 4e pg 13 and B239 are written implies the circle is outside the hexagon otherwise it wouldn't effect the entire hex.

Yes, we know the inradius (center to side) is 0.5 yards but is that the radius of the spell's 1 hex area of effect or is it the circumradius (center to vertices)?

If it is the later than that one hex spell is already spilling over into the neighboring hexes (but the amount is so small it can be ignored) and gives us a radius of effect of ~1.05 yards^2 (0.5 = √3/2 x a where a = R, or radius of 0.577)

See Hexagon Calculator for more information on a hexagon than you really need. :-)