Page 87 - DnD 5e - Xanathar's Guide to Everything

someone might cast charm person on a creature be-
lieved to be a humanoid, not knowing that the target is
in fact a vampire. If this issue comes up, handle it using
the following rule.
If you cast a spell on someone or something that can't
be affected by the spell, nothing happens to that target,
but if you used a spell s lot to cast the spell, the s lot is
still expended. If the spell normally has no effect on a
target that succeeds on a saving throw, the invalid target
appears to have succeeded on its saving throw, even
though it didn't attempt one (giving no hint that the crea-
ture is in fact an invalid target). Otherwise, you perceive
that the spell did nothing to the target.
O tl\GRl\M 2. 1:
CONE TEMPLATE
AREAS OF EFFECT ON A GRID
The Dungeon Master's Guide includes the following
short rule for using areas of effect on a grid.
Choose an intersection of squares as the point of
origin of an area of effect, then follow the rules for that
kind of area as normal (see the "Areas of Effect" section
in chapter 10 of the Player's Handbook). If an area of ef-
fect is circular and covers at least half a square, it affects
that square.
That rule works, but it can require a fair amount of
on-the-spot adjudication. This section offers two alterna-
tives for determining the exact location of an area: the
template method and the token method. Both of these
methods assume you're using a grid and miniatures of
some sort. Because these methods can yield different
res ults for the number of squares in a given area, it's SPHERE T EMPL ATE
not recommended that they be combined at the table-
choose whichever method you and your players find eas-
ier or more intuitive.

TEMPLATE METHOD
The template method uses two-dimensional shapes
that represent different areas of effect. The aim of the
method is to accurately portray the length and width
of each area on the grid and to leave little doubt about
which creatures are affected by it. You'll need to make
these templates or find premade ones.
Making a Template. Making a template is s imple. Get
a piece of paper or card stock, and cut it in the shape of
the area of effect you're using. Every 5 feet of the area DIAGRAM 2 .3 : SQ.Ul\RE
equals 1 inch of the template's size. For example, the AREA USING TOKEN S
20-foot-radius sphere of the fireball spell, which has a
40-foot diameter, would translate into a circula r tem-
plate with an 8-inch diameter.
Using a Template. To use an area-of-effect template,
apply it to the grid. If the terrain is flat, you can lay it on
the surface; otherwise, hold the template above the sur-
face and take note of which squares it covers or partially
covers. If any part of a square is under the template, that
s quare is included in the area of effect. If a creature's
miniature is in a n affected square, that creature is in
the area. Being adjacent to the edge of the template
isn't enough for a square to be included in the area of
effect; the square must be entirely or partly covered by
the template.
You can also use this method without a grid. If you do
so, a creature is included in an area of effect if any part DtAGRAM 2. 4 : 5Q.UARE
of the miniature's base is overlapped by the template. AREA WI T H T OTAL CovER

CHAPTER 2 I DUNCEON MA STER'S TOOLS