Arcade machines, known for their fixed hardware and software configurations, traditionally limit player-generated content or mods due to their closed ecosystems. However, modern arcade systems and retro enthusiasts have found ways to introduce customization.

1. Closed Systems: Most classic arcade machines run on proprietary hardware and ROMs, making mods difficult without specialized tools. Unauthorized modifications often violate terms of service.

2. Modern Arcade Solutions: Newer arcade cabinets, like those using PC-based systems (e.g., Arcade1Up), allow limited modding. Players can add games via USB or software hacks, though this may void warranties.

3. Emulation & Homebrew: Enthusiasts use emulators (e.g., MAME) to run modified or fan-made games on custom-built arcade setups. Homebrew communities create original content for retro hardware.

4. Developer-Supported Mods: Some indie arcade games (e.g., "Killer Queen") enable level editors or community content, blending arcade traditions with modern modding culture.

While arcade purists prefer authenticity, modding keeps the scene vibrant by expanding gameplay possibilities. Always check legality before modifying commercial machines!