Line of Effect vs Line of Sight

( ⇪ House Rules )

In situations where you have line of sight but not necessarily true line of effect (such as when looking through a glass window or shutter), generally use the description of the effect to determine whether you need mechanical (“true”) line of effect.

The following new terms categorize certain kinds of effects:

  • “Grenade-like”: Some kind of object is hurled or fired at a destination (which is usually a square), and optionally may have a burst or spread or multi-target or other area effect centered there (i.e. magic missile, fireball, hail of crystals, sleep, slow, etc.).
  • “Ray-like”: Some kind of object (usually a visual ray) is hurled or fired at a destination (which could be a square) as a ranged touch attack. (i.e. scorching ray, crystal shard, etc.)
  • “Bullet-like”: Some kind of object is hurled or fired at a destination (which could be a square) as a non-touch ranged attack. (i.e. giant’s wrath, Invisible Needle, etc.)
  • “Spray-like”: Some kind of object is delivered through a cone-shaped burst effect that originates at the user.
  • “Jet-like”: Some kind of object is delivered through a line effect that originates at the user.
  • “Bomb-like”: Some kind of object is delivered through a burst or spread effect that originates and is centered on the user.

Effects that do not describe one of these categories as a means to get from you to their destination do not require true line of effect and only need line of sight (even if that line of sight is through a glass window, a screen, or scry). However, the physical destination of the effect must still be within the effect’s stated physical range (“range+radius” for some area effects) ignoring obstacles (Yes, this means you’ll often have to look up the flavor text for each effect if it’s from the SRD/OGC, but that’s nothing new). If this puzzles you, you can think of it as “the influence of your magic does not spread beyond the physical range of the spell”.

Use your best judgement on what these categories do to intervening obstacles (such as whether they count as “soft cover” or whether it’ll damage, destroy, or move the obstacle in some way).

Realize that a lot of psionic powers do not mention any sort of need for a true line of effect. Additionally, the psionicist could “dispense with displays” (and generally will always attempt to anyway since there’s no negative cost for failure) to completely remove that display. However, if the power’s description directly describes an effect of one of these categories as a means for the power to get from the psionicist to the destination, then the dispense with display option will not dispense with that aspect of the display (and thus, still requires true line of effect).

For portal-like effects, the squares on one end of the portal are considered adjacent to the squares on the other end of the portal for the purposes of line of effect and line of sight (unless stated otherwise). This particular rule ignores the limits on interplanar range such as written in the clairvoyance spell (the portal has to at least be within range of the clairvoyance spell). Effects which attempt to cross planes use the location of the nearest physical connection between those two planes (such as a portal) when determining if something is within the stated physical range.

Mirrors, Visual Rays, and Light

If an effect is visually a ray (ex. “Scorching Ray”) and such an effect is aimed at a mirror or other reasonably reflective surface of any kind, the ray bounces off of the mirror as appropriate. Likewise, if the effect is a light effect (such as having the “light” descriptor), it should also bounce off of all mirrors as appropriate. In either case, be sure to consider the angle of incidence to the mirror so far as whether it can hit something reflected in the mirror.

Only the reflectiveness of the reflective surface (i.e. “is the mirror cloudy” or “how still is the water”) should determine whether there are any detriments to the effect or penalties to its chance to hit something after the reflection. GMs should use their best discretion on how reflective a surface is, but generally if a player has direct control over the reflectiveness of the surface somehow (such as personally creating the reflective surface through the mirror or create water spell) then they should determine how reflective the surface is (initially, in the case of create water).

There’s a new special property for metal shields called “mirrored”. It comes automatically with any masterwork metal shield, although you can add it onto any non-masterwork metal shield by doubling the normal mundane price for the shield. A mirrored shield lets you add your shield bonus to your Touch AC versus attack rolls from visual rays and light effects. If the effect would have hit your Touch AC if not for your shield or its bonus, you can use an immediate action to redirect the effect back at its originator. The spell or ability attacks the original caster (who makes a new attack roll using the same modifier as the original attack). If it hits, the caster is subject to the normal effect of the spell or ability. If a single effect misses you more than once at the same time (such as scorching ray cast by a high-level caster), you can redirect each portion of the spell that missed. Using the example above, if you were missed by two of the three rays from an 11th-level wizard’s scorching ray spell, you could redirect only those two rays (but not the one that hit).

Line of Effect vs Line of Sight

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