To the best of my knowledge, all of the races who can start in the Underdark possess either Dark Vision or Low-light Vision. Not only is it not necessary for any Underdark character to cast a Light spell on themselves, it's also highly lore and immersion-breaking. If you give away your position in the tunnels and caves of the Underdark like a lighthouse on the surface, you're asking for trouble.
If Phar sees many more of this, he's going to start killing off people soon (with PvP Consent only).
---- Edit ----
Acceptable sources of light
- Bioluminescent
- Faerie Fire
- Low-intensity candle light
- Dancing Lights (RP'ed from Drow Racial Light spell)
- Light (self)*
- Torchlight
- Lantern
- Natural sunlight (with Daylight Adaption)
- Light (others)*
- Sunbeam
- Sunburst
- Natural sunlight (without Daylight Adaption)
- Lightning spells (Lightning Bolt, Chain Lightning, Electric Loop, etc)
Special:
Light in the UD is a big no-no, except when it is one of the acceptable sources. Casting the Light spell on another character, without prior consent, should be consent to PvP, since you're intentionally causing the other character discomfort or pain, as well as making them a visible target in the UD.
