Infravision

According to this definition, infravision is the ability to sense or "see" heat. The best comparison is to thermal imaging equipment used by the armed forces of many different nations today. This special sense is limited to a 60-foot range. Within this range, characters can see the degrees of heat radiated by an object as a glowing blob translated into various shades of red.

Large heat sources will temporarily blind characters with infravision just as looking at a bright light blinds those with normal vision. Thus, those attempting to use infravision must make the effort to avoid looking directly at fires or torches, either their own or the enemy's. Also, there may be times when it is impossible to tell the floor from the walls in most underground areas. All of it is the same temperature, after all.

Note: This version of infravision originally appeared in the 2nd Edition Dungeon Master Guide for the Advanced Dungeons & Dragons game by TSR. Its inclusion here is for the purposes of providing context for the campaign only.