This glass cased device is fitted to the Guidance System and Directional Unit. When installed it uses a random field frame to ensure that the destination coordinates are random. It also keeps a TARDIS from getting a lock on galactic zero centre Every time it is activated the operator must input a random seed setting. This seed number is the basis of the improbability algorithms.
The Randomiser can be overridden if the operator wishes to travel to a specific time zone. This is done by deactivating all of a TARDIS' travel circuits and manually inputting the space-time coordinates. By disabling only some of the travel circuits it is possible to partially engage the Randomiser This allows the operate to set broad guidelines as to the approximate geographical area and temporal arrival point, but to leave the exact date and location up to the Randomiser.
Randomisers are often used by renegade time travellers who are being actively pursued by one of the temporal powers. For this reason it is illegal for a Time Lord to own or construct one of these devices. Randomisers can also be cannibalized to form a random field frame for a Tachyon Generator.
The following color code is used:
- Black: For information from the TV Series, including Dimensions in Time, and 1996 TV Movie.
- Blue: For information from the Novels and Audios including Target, Virgin, BCC, and Big Finish.
- Green: For information from 'licensed' reference sources such as the Technical Manual, Doctor Who Magazine, and the Role Playing Games.
- Red: For information from unofficial sources -The Faction Paradox series, behind the scenes interviews, author's speculation, and popular fan belief.
The TARDIS Technical Index is copyright Will B Swift.