Zapping a wand of make invisible makes the target monster invisible. If you zap it at yourself, you become permanently invisible, unless you are wearing a mummy wrapping. Zapping the wand downward on a square with an engraving will make the engraving disappear. In SLASH'EM, wands of make invisible can also make objects invisible. This simplifies the process of identifying the wand. The invisibility can be circumvented by wearing a mummy wrapping.