Not every MAME release breaks ROMs, but 0.250 introduced several ROM changes that affect common sets.

An update labeled for a specific MAME release generally includes one or more of the following:

Several previously missing bootleg versions of popular arcade games were added, including alternate region releases of Street Fighter II and Metal Slug.

MAME 0.250 significantly broadened its scope beyond arcade cabinets:

For archivists and enthusiasts, the following strategy is recommended for updating to the 0.250 set:

Release Date: February 23, 2022 Software Version: MAME 0.250 Category: Multi-System Emulation / Digital Preservation

No discussion of an updated ROM set is complete without addressing copyright. MAME itself is legal—it is emulation software. However, downloading commercial ROMs remains a grey area.

Most arcade games from the 1980s–2000s are still under copyright. However, many rights holders have abandoned enforcement, and the MAME project operates as a preservation effort. If you want to stay fully legal, you can:

That said, the emulation community recognises that updated ROM sets like MAME 0.250 are essential for historical preservation. Use your own judgement and local laws.