The Debug Mode is a feature implemented into the M.U.G.E.N engine that enables the player to see the damage, speed and other stats on-screen. As its name suggests, its main purpose is to detect any bugs a character may possess, but it's mostly used by players as a method of cheating.

The debug mode is disabled by default, but it can be enabled by Ctrl+D. In order for debug mode to be active by default, it must be enabled in mugen.cfg first. It is also possible for debug keys to be enabled while debug mode is disabled, again though mugen.cfg.

Debug keys

The debug keys are enabled by default but can be disabled by editing the file mugen.cfg in the data folder.

F1

This debug key is the most famous one, instantly KO-ing player 2 by setting its life to 0. Certain characters contain coding that keeps them from being KO'd in this manner.

Ctrl-F1

Has the same effect as F1, but KO's player 1 instead of player 2.

F2

Sets both players' life to 1. As with F1, this debug key is also neutralised by particular characters.

Ctrl-F2

Sets only player 1's life to 1.

Shift-F2

Sets player 2's life to 1.

F3

Maxes out both players' power.

F4

Restarts the current round.

Shift-F4

Restarts the entire match, intros and all, as well as reloading player data.

F5

Sets the time to 0, resulting in a Time Over.

F12

Takes a screenshot of the game, saved in .pcx format (or .png format in M.U.G.E.N 1.0). This can be used even if the debug keys are off. Screenshots are saved in the same location as mugen.exe.

Ctrl-# (replace # with 1-4)

Toggles AI of player #.

Ctrl-Alt-# (replace # with 1-4)

Toggles existence of player #.

Ctrl-C

Toggles display of collision boxes.

Ctrl-D

When debug mode is off, it turns the debug mode on. Afterwards it cycles between each character's (or helpers', if they have been created) info, eventually turning debug mode off.

Ctrl-F

Cycles through frameskip speeds (default is auto).

Ctrl-I

Resets both players to the standing state.

Ctrl-L

Toggles display of the life and power bars.

Ctrl-S

Toggles speed-up, which makes M.U.G.E.N run at its fastest setting (will appear to run slowly if the machine being used is not powerful enough).

Ctrl-T

Toggles auto-refill of life and power bars (only works during quick versus).

Ctrl-V

Toggles V-sync, which helps prevent moving images from "shearing".

Space

This maxes out time, and both players' life and power. This can be used even if the debug keys are off.