Use MUGEN Fighter Factory 3 (free tool). Open system.sff . Go to Sprite > Resize All Sprites . Resize by 200% using "No Filter" (for pixel art) or "Linear" for smoothed lifebars. Save as SFFv2.

inside your Mugen 1.1’s /data/ directory. Example: Mugen 1.1/data/MyScreenpack/

: Most legacy M.U.G.E.N stages and characters were originally designed for 320x240 or 640x480. A 4:3 screenpack ensures these assets fill the screen without awkward black bars or being stretched horizontally. Deep Customization : In M.U.G.E.N 1.1, the system.def