One major thing needs to be understood about this card. It stops the corp from WINNING the game by having 7 points, it doesn't do anything to stop the corp from GETTING to 7 points. It doesn't stop them from advancing or scoring at all (like clot and price of freedom), so if they have an agenda in hand or on the board, Black File does nothing to prevent them from scoring it and saying "I win" 2 turns later. That means it's only useful in an extremely close game where you both are at match point and you need 2 extra turns to try to make sure they don't score first while you dig for the winning agenda.......and it costs you 5 credits. Plus it's only 1 in the deck, so the consistency of this card is very weak. It can feel great when it works, but very rarely will you have it in hand AND need it AND have the extra money for it at the same time. It's nowhere near reliable enough to be put in a serious deck. Disappointing, I know, but true.