Types of Senses
This page details how the senses work in combat and how they interact with stealth and invisibility.
There are many types of senses. For game purposes, all that we worry about are the 'useful' ones. We don't really need to worry about your sense of balance, or proprioception, or a monster's ability to know that it needs to take a poop. For our purposes, we just need to concern ourselves with the senses useful for playing.
In general, these senses fall into four main categories:
- Sight
- Sound
- Smell
- Exotic
Nearly all monsters have the same targeting senses as your typical human, represented as Standard Senses. The senses below define these senses, as well as the other extraordinary senses that monsters (and some player characters) might possess. Creatures which are missing one or more of the standard senses usually state that they are blind to a particular sensory group (Sight, Sound, Smell). All creatures are assumed to be Blind to the exotic sensory group unless their entry explicitly states they possess one or more exotic senses.
Table: Visual Senses
| Sense | Range | Line of Sight? | Line of Effect? | Combat Targeting | vs. Stealth |
|---|---|---|---|---|---|
| Standard Vision | Varies | Yes | No | Yes | Perception check |
| Low-Light Vision | Varies | Yes | No | Yes | Perception check |
| Darkvision | Varies | Yes | No | Yes | Perception check |
| Heartsight | Varies | Yes | No | Yes | Provides a 10' radius of light emanating from each humanoid in range |
Table: Audio Senses
| Sense | Range | Line of Sight? | Line of Effect? | Combat Targeting | vs. Stealth |
|---|---|---|---|---|---|
| Standard Hearing | 20 feet | No | Yes | Perception check, 50% miss chance | Perception check, 50% miss chance, ignores invisibility |
| Keen Hearing | 60 feet | No | Yes | Perception check, 50% miss chance | Perception check, 50% miss chance, ignores invisibility |
| Precise Hearing | 20 feet | No | Yes | Adjacent creatures | Perception check, ignores invisibility |
| Echolocation | 30 feet | No | Yes | Yes | Perception check, ignores invisibility |
Table: Olefactory Senses
| Sense | Range | Line of Sight? | Line of Effect? | Combat Targeting | vs. Stealth |
|---|---|---|---|---|---|
| Standard Scent | 10 feet | No | Yes | Survival check, 50% miss chance | Survival check at -10, 50% miss chance, ignores invisibility |
| Scent | 30 feet | No | Yes | Survival check, 50% miss chance | Survival check, 50% miss chance, ignores invisibility |
| Keen Scent | 60 feet | No | Yes | 20% miss chance | Survival check at +2, 20% miss chance, ignores invisibility |
| Perfect Scent | 120 feet | No | Yes | Yes | Survival check at +5, ignores invisibility |
Table: Exotic Senses
| Sense | Range | Line of Sight? | Line of Effect? | Combat Targeting | vs. Stealth |
|---|---|---|---|---|---|
| Tremorsense | Varies | No | Yes | Yes | Perception check at +5, ignores invisibility |
| Blindsense | Varies | No | No | Yes | Perception check at +5, ignores invisibility |
| Lifesense | Varies | No | No | 20% miss chance | Perception check at +5, ignores invisibility, 20% miss chance |
Light and Darkness
The visual senses use light of various spectrums to allow the creature using it to see. Light is divided into bright light, dim light, darkness, and true darkness (as with the Deeper Darkness (Spell) spell).
Bright Light
Any creature with a visual sensory organ can see an unlimited distance in bright light, assuming that no object blocks line of sight (which can include the curvature of the planet). The visual horizon is the critical determinant for distance of vision in bright light when viewing distant objects in vast, open spaces:
- For an observer standing on the ground with average height, the horizon is at a distance of 2.9 miles.
- For an observer standing on the second story of a building or a ship's deck (10 feet), the horizon is at a distance of 3.8 miles.
- For an observer standing on a hill or tower (100 feet), the horizon is at a distance of 12.2 miles.
- For an observer standing at the top of an average mountain (13,000 ft), the horizon is at a distance of 139 miles.
- For an observer atop the tallest of mountains (30,000 ft), the horizon is at a distance of 211 miles.
Normal Light
This has been removed from the game. Spells or abilities which reference normal light should be amended to state 'bright light'.
Dim Light
Standard visual sensory organs function poorly in dim light, and creatures in dim light gain concealment against creatures with standard vision. Concealment grants the concealed creature a 20% chance to be missed by attacks in combat.
Typically, a bright source of light, such as a torch, provides dim light an equal distance to its bright light radius, beginning at the edge of that bright light radius. Thus, a torch provides bright light to 30 feet, and dim light beyond 30 feet out to 60 feet. Moonlight and starlight are the most common sources of dim light that do not provide a commensurate amount of bright light. Some magic items are also capable of producing dim light without bright light.
Darkness
The area outside of any light source, beyond the reach of dim light, is considered darkness. Darkness grants total concealment to creatures within it, when perceived by creatures with standard vision. Total concealment grants the concealed creature a 50% chance to be missed by attacks in combat.
Darkness can also be created by magical spells, such as the Darkness (Spell) spell. In this case, unless the spell specifically states otherwise, Darkvision still functions within the darkness.
True Darkness
This is magical or elemental darkness, and cannot be penetrated by visual senses. It goes beyond the absence of all spectrums of light, to the point of being anathema to light, actively absorbing or destroying it. All creatures in True Darkness gain total concealment (50% miss chance) against any visual senses.