Glow

Not to be confused with magic contamination, which was once simply called glow

In Crawl, there are several things that can make your character glow. The only effect that glowing itself has is to negate any source of invisibility; however, glowing is caused by sources that are usually somewhat dangerous in and of themselves:

• Excessive magic contamination: This is the most dangerous, as it will very likely leave you with some bad mutations as it decays.
• The spell Corona: This makes you easier to hit, in addition to negating invisibility. Not many monsters cast it, but the enchantress and many player ghosts do. It can be resisted via magic resistance.
• Sticky flame: This causes damage over time that can be resisted with fire resistance, and also trashes your scrolls. The effect itself is only resistible by wearing mottled dragon armour, or being a mottled draconian.