Sonic 3D Secret Level Select

It’s not often that I post non-Pokitto things, but I felt the need to share this because it’s about game design and video game history so I think it’s somewhat relevant. (Also it’s pretty funny and slightly clever.)

For those who can’t (or can’t be bothered to) watch the video…

SEGA used to have a really strict review process for their games - if the game crashed even once during testing it would be sent back to the developer, who would have to fix it and reregister.

So to get around this, some developers realised that they could catch the errors and make it look like it was part of the game, so that anything that should have been a bug just caused an easter egg.

In the case of Sonic 3D, its programmer (Jon Burton, the bloke narrating the video) decided to not just try to detect errors, but to fill the unusued vector table entries with jumps to a level select screen (which apparently attempts to detect errors and clean things up), so that any error that the CPU detected, no matter how small, would put the player at the level select screen. Most things in game don’t trigger it, but wiggling the cartridge causes enough electrical noise to activate it.

It’s not really good programming practice (or good for your console) but it’s certainly an amusing story nonetheless.


This same guy has several other interesting game coding related stories

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Well, he ought to, he founded Traveller’s Tales after all. :P

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