There is no one button Fatality code for the N64,only unlimited Fatality time.The psx does though.Go to the options screen hold L1,L2,R1,R2 and up on the d-pad.Wait for the screen to shake and the green ? in the middle will be unlocked.THe one button Fatality option is in there.
Sqaure=Brutality
X=Babality
Triangle=Fatality 1
O=Fatality 2
L1 or R1=Frienship
L2 or R2=Animality
There is no stage Fatality button though

The person is talking about MK4, you're talking about MKT.
This is a description of how to get to the cheat menu in MK4 PSX, the code you're looking for might or might not be in here, as I don't have this version of MK4.
Start a 2 player game and at the versus screen:
Player one: LP three times, LK twice
Player two: LP twice, Block once, LK three times
When the match start, pause, and exit the to the main menu. Select Options, highlight ''Vs Screen Enabled'' and hold Run + Block. After a few seconds, you'll hear a laugh, continue to hold the buttons down until the ''Cheats'' menu appears.

Alpha_Q_Up Wrote: There is no one button Fatality code for the N64.

What are you talking about? There is a one button fatality code for the N64 version of MK4.

The_Purple_Bunny Wrote: The person is talking about MK4, you're talking about MKT. This is a description of how to get to the cheat menu in MK4 PSX, the code you're looking for might or might not be in here, as I don't have this version of MK4. Start a 2 player game and at the versus screen: Player one: LP three times, LK twice Player two: LP twice, Block once, LK three times When the match start, pause, and exit the to the main menu. Select Options, highlight ''Vs Screen Enabled'' and hold Run + Block. After a few seconds, you'll hear a laugh, continue to hold the buttons down until the ''Cheats'' menu appears.

Thanks purple bunny. I rented the game before and the cheat i knew for the N64 didn't work like it did on the computer version. I saw some codes on MKnightmares, but i don't remember any of them. Since MK nightmares doesn't excise, i though i should ask if anyone else knew it. Thanks.