The Rainbow Crystal is a magical crystal with hypnotizing powers, appearing in the Price of Peace campaign in Heroes of Might and Magic IV. The crystal is first mentioned in the Rainbow Crystal scenario, where Solmyr is sent by king Gavin Magnus to retrieve the crystal, so that king Magnus can use its powers to control his unreliable red dwarf allies. With the aid of Holman, the only survivor of the adventuring party that located the crystal, Solmyr manages to defeat Dreggar, the necromancer who now owns it, and bring the crystal back to his master.