Ambient complexity
From Tardis Wiki, the free Doctor Who reference
According to the TARDIS information system, ambient complexity was an environmental condition which could cause a regeneration to fail. The solution to the problem of a "busy background" was, according to the information system, a Zero Room or an "eminently more effective" real, neutral location like the "habitation" of Castrovalva. (TV: Castrovalva [+]Loading...["Castrovalva (TV story)"])
