During the switch-over from 2nd edition to 3rd and later editions of the game, infra- and ultra-vision got subsumed into the character/monster traits of Low-Light Vision and Darkvision, since those were their actual functions in old-school game terms.
|SQUAWK! I see you in a whole different light.|
Their disappearance provoked a lot of nostalgia in me, and I could never quite let them go. I always thought they could give excellent perks to PCs that were separate from just being able to see in the dark.
In the old rules, for instance, infravision could be optionally defined as the ability to detect creatures and objects by their natural heat emissions. This could grant bonuses on checks to detect invisible creatures, provided they had a warm-blooded metabolism.
But the original game didn't have many good ideas what to do with ultravision, the ability to perceive colors in the ultraviolet spectrum. The descriptions of the ability provided in older editions were, as noted, scientifically embarrassing. But they needn't have been.
Unlike infravision, something like ultravision actually exists in nature; more than half of all bird species can see ultraviolet light. And when you do a little perfunctory reading on its possible evolutionary advantages, some game effects are immediately suggested.
The prevailing hypotheses are that bird UV vision evolved because it provided advantages to foraging and hunting (some fruits are more visible in the UV spectrum, as are many prey animals' excretions), signalling and camouflage (making them more visible to each other, but less visible to predators who can only see into the violet range), and sexual selection (flashier birds get more mates).
Thus, an old-school fantasy RPG about animal characters can revive Ultravision, and make it better! Here's my preliminary write-up for the Ultravision Species Trait, which will ultimately be found in the descriptions for several bird and fish species:
- Ultravision: In addition to normal vision, you can perceive colors in the ultraviolet spectrum. This grants you a +2 bonus on all Herbalist and Scout lore checks to gather nutritious fruits and berries (Herbalist lore), to spot hidden predators, or to track other animals by their excrement trails (Scout lore). When tracking, this species trait stacks with any bonus you receive from the Scent ability.