Rule: Areas of Effect

Summary

An area of effect always has a point of origin and extends out from that point. There are three types of areas: cones, lines, and radiuses.

In this game, many types of ranges will be referred to as certain areas of effect, such as a line cone of effect for Breath Weapons, or a radius for light sources or burst-type effects. These are Areas of Effect, and will be referred to as such.
The main types of Areas are Cones, Lines, and Radiuses. Others exist, but they are considered special and/or will be indicated as such.

Area Types

Cone

A Cone shoots out from you in a quarter circle on the grid. When you aim a cone, the first square of that cone must share an edge with your space if you're aiming , as if you are moving at a diagonal. If you're Large or larger, the first square can run along the edge of the space you occupy (or at the nearest squares, if using a grid). You can't aim a cone so that it overlaps your space. The cone extends out for a number of feet, widening as it goes (if using a grid, every single 5 ft square vertically expands the cone 1 square horizontally, or 2 squares total).

As an example, if you cast the Burning Hands spell, you create a cone of flames that originates at the edge of one square of your space and affects a quarter-circle area 15 feet on each edge.

If you make a cone originate elsewhere, use these same rules, with the first square of the cone using an edge or corner of that creature or object's space instead of your own.

Line

A Line shoots forth from you, following a straight path in a direction of your choosing. The line affects each creature whose space it overlaps. A line is usually 5 ft wide, but can be made wider with certain effects and/or unless the effect says otherwise

For example, the Lightning Bolt ability has an area that is a 5 foot wide 60-foot line.

Radius

A radius, sometimes called an emanation or a burst, is an area around a space or unit. The radial area extends out to a specified number of ft in all directions, including the third dimension.

The stated radius does not include the space the unit is taking up (meaning a radius of 5 ft is, in reality, 10 ft if measuring from the center of where it starts, but 5 ft if measuring from the edge). When the radius comes from a creature, as with an Aura, it includes the creature's space (i.e. meaning a creature that is Large or Larger has a larger radius).

For instance, a Torch has a radius/emanation of 15 ft of bright light, lighting up a 5 ft / 1.5m square area and ~15 ft / ~5 m radius around it (and does not grow in size, if held by a Large creature). Unless the text states otherwise, the creature creating a radius effect chooses whether the creature at its center is affected.

Other Areas of Effect