Invisibility

Invisibility is an intrinsic with the effect that monsters without see invisible cannot see you. As such, they will have difficulty locating you and will usually miss when attempting to attack you unless you stay in one location for an extended length of time.

An invisible player will be prevented from entering shops by the shopkeeper ("Invisible customers are not welcome!"). This can be circumvented by wearing a mummy wrapping, which will render you visible while you are wearing it.

Write more on uses, strategies, etc.?