The Jargon File (version 4.4.7, 29 Dec 2003):

wizard mode
 n.

    [from rogue] A special access mode of a program or system, usually
    passworded, that permits some users godlike privileges. Generally not used
    for operating systems themselves (root mode or wheel mode would be used
    instead). This term is often used with respect to games that have editable
    state.


The Free On-line Dictionary of Computing (30 December 2018):

wizard mode

    [rogue] A special access mode of a program or
   system, usually password protected, that permits some users
   godlike privileges.  Generally not used for operating
   systems themselves ("root mode" or "wheel mode" would be used
   instead).  This term is often used with respect to games that
   have editable state.