Emperor lich is a type of monster in ADOM. They are very powerful magic users that can appear (rarely) on areas of very high danger level. One is always found in a greater vault of undead, and some luckless players have claimed to encounter them whilst grave robbing. Whilst they are often regarded as one of the more dangerous monsters in the game due to their magical abilities, in terms of base stats emperor liches are not one of the toughest late game threats. Death ray resistance is a must when fighting one; weapons and ammo of undead slaying also go a long way.