The Telepathic Circuits allow the TARDIS to ‘communicate’ with its operator and others. Without it, a Time Lord would have greater difficulty operating and repairing the TARDIS and, in addition, would be reduced to learning alien languages the hard way.
All TARDIS units have Telepathic Circuits and this provides the basis for many of its operating systems, particularly those for translation and telepathic transmission. For more information see the section on the TARDIS Telepathic Systems.
If these circuits are damaged, all rolls concerning the operation or repair of the TARDIS are increased in Difficulty by 3 and the players lose the use of the Telepathic Translation Field (although the Translation Circuit will still be functional and available via the Communications Console for manual translations).