The 65-year-old author initiated a new fundraiser Thursday to raise money for Wild Spirit Wolf Sanctuary and Food Depot in Santa Fe, N.M., where he lives with his wife, Parris McBride.
Every person who donates has the chance to win a helicopter tour of the sanctuary with Martin, but the ultimate prize is at the $20,000 level.
Two lucky fans who donate the sum will be written into a future A Song of Ice and Fire book and subsequently killed off. There is one male character and one female character available, and the person can choose their "character's station in the world (lordling, knight, peasant, whore, lady, maester, septon, anything)."
"You will certainly meet a grisly fate," the contest page reads.
Martin has written five ASoIaF books thus far, and has yet to announce a release date for The Winds of Winter. Editor Anne Groell recently revealed the series may require eight books instead of seven. The novels have been adapted for the HBO television series Game of Thrones.