Sega's cartridge library has fewer four-figure titles than Nintendo's, which has kept the repro market smaller, but the top of the market is absolutely targeted.

Screws

Genesis/Mega Drive cartridges are normally held by a 4.5mm gamebit security screw, the larger sibling of the 3.8mm bit the Nintendo carts use, so bring both. Sega was far less consistent than Nintendo about this: the shell went through several revisions across the console's life, screw counts and types vary between them, and some carts (many Master System releases especially) are snap-together with no screw at all.

That variation is exactly what makes the screw a weak test on Sega. A Genesis cart with an unexpected fastener is worth a note, not a verdict. Go to the labels and the board.

Label tells

• Genuine Genesis labels vary considerably across the console's life (the early "high-tech" style, the later standardized style). Verify the label style matches the title's release window.
• Sega end labels and spine text are frequently wrong on repros.
• Master System carts used both card-style and standard cart formats depending on region and era. Verify format against documented releases.

Shell tells

• Genesis shells carry molded Sega markings and part numbers.
• Check the cartridge's rear ridges and the tab layout. Region-specific shell shapes (Genesis vs. Mega Drive) should match the label's region.

Board tells

Genuine Sega boards carry 171-xxxx board numbers silkscreened on the PCB, with Sega- or licensee-marked mask ROMs. Repros show generic boards with flash chips.

Most commonly faked Sega titles

• MUSHA
• Crusader of Centy
• Alien Soldier
• Contra: Hard Corps (PAL)
• Mega Man: The Wily Wars
• Pulseman
• Panorama Cotton
• Sonic 3D Blast (PAL variants)
• The Master System PAL-exclusive library