The Genie appears as a random event. The Genie appears near players and gives them an experiencelamp, which may be rubbed to raise a selected skill's experience by 10 times the current level of the particular. For example, if the player has level 30 in Herblore, they would gain 300 Herblore experience if the skill is chosen.
Therefore, a lamp can be useful in gaining Prayer and Slayer experience, especially at higher levels, where conventional methods either provide very little experience or is very expensive.
If ignored the genie would eventually teleport the player away before the Optional Randoms update.