If there is a rule called The Black Cat, and a rule called Malfeasances, add the following to the end of The Black Cat:

If an Explorer is the only Explorer in a room, and the Black Cat is also in that room, and no Explorer is currently Possessed by Katastrophe, then at the start of the next Mansion Phase that Explorer is Possessed by Katastrophe.

If an Explorer is in the same room as the Black Cat, and that Explorer is currently Possessed by Katastrophe, and it is not the Mansion Phase, then they gain access to a special Malfeasance, and that Malfeasance is automatically made their Ploy (and cannot be changed, beyond specifying a new target, as long as these conditions remain true):

{| class="wikitable"
|+ Special Malfeasance
! Name || Effect || Restrictions
|-
| Repossession || The Explorer currently possessed by Katastrophe ceases to be, and the named other Explorer becomes possessed by Katasrophe || A single other Explorer must be named (or, if not, is randomly selected)
|}

If there is a rule called Malfeasance, AND if Proposal: The House of Katastrophe was enacted, change the text “Privately roll a DICE4, add 2, and increase Dread by that amount” in the rule Mansion Phase to read as follows:

Increase Dread by 1 for each Ploy, Planned Action carried out as part of a Malfeasance, or Supernatural Action to have taken place in the current Mansion Phase, plus or minus a random value between -1 and 1 inclusive (to a minimum of zero).