Which Genesis / Mega Drive Games Are Region Locked? Sega's TradeMark Security System, or TMSS Region Locking Via Physical Cartridge Shape Sega's Early Region Locking And TMSS Explained On this page: Guide: How To Play Mega Drive Games On Sega Genesis - Region-Locking And TMSS Explained
The end result of all of this is that it's often quite hard to be sure what game will work on which Genesis / Mega Drive system – hence this handy guide. This system was designed to prevent companies from making Genesis / Mega Drive games without a licence, but it also doubled up as a regional lock-out system.
What makes this console so confusing is that more than one method of region protection was used during its lifespan, with the earliest example being purely physical, before Sega introduced its TradeMark Security System – or 'TMSS' for short. One of the first systems to employ a more advanced type of region locking was the Sega Mega Drive, or Genesis, as it is known in North America. However, not so long ago, this wasn't the case – and almost every console manufacturer employed some form of region protection to prevent games from being played outside of their country of publication. Region locking is largely a thing of the past these days, with Sony, Microsoft and Nintendo all choosing to make their consoles region-free – so you can play software from any region, regardless of where you are in the world.
