Static backgrounds are fine but a flickering torch makes a stage feel alive. To animate something, we use type = anim instead of type = normal, and point it at an action defined further down in the file.
The animated layer:
[BG AnimatedThing]
type = anim
actionno = 10
start = -50, 80
delta = 0.8, 0.8
mask = 1
The animation itself — each line is one frame, with this format: group, image, x, y, ticks. 60 ticks = 1 second.
[Begin Action 10]
1, 0, 0, 0, 6
1, 1, 0, 0, 4
1, 2, 0, 0, 6
1, 1, 0, 0, 4
That's it — when MUGEN reaches the end of the action, it automatically loops back to the top.
Want a faster flicker? Lower the tick numbers (try 3, 2, 3, 2). Want slower? Raise them. The numbers are frames, not seconds.
Try it
Add a SECOND torch on the right side of the stage. Copy the whole
[BG AnimatedThing] block, paste it below, rename it to
[BG AnimatedThing2], and change
start = -50, 80 to
start = 80, 80. Both torches will share the same animation that's fine.