Confusing Super Mario optical illusion just keeps giving

Super Mario is the subject of an optical illusion that's been baffling the internet for years now. Shared on Reddit, the image is of Mario running *on* a staircase, but the question is: is he running up, or down? 

With the angle of the stairs ambiguous, the Nintendo star could be running either way from this still image, which has caused untold debate. But luckily, since this picture is originally from an episode of Super Mario Bros Super Show, there's an easy way to find out – and we've shared below. But first, check out the illusion for yourself and see what you think (then head to our list of the best optical illusions ever).

"He is going up look at his left foot it gives it away," one Reddit user points out. But it's not so simple according to another, who applies a more complex theory:

"I get what people are saying with it looking up from the feet but I remember as a kid visiting castles that staircases were only ever one way to prevent right handed (attacking) swordsman coming up the stairs from being able to get a full swing off...so by that logic he should be going down....". 

A stellar point. And another great question comes up, "Who builds stairs with the steps angled 45 degrees from horizontal?" someone asks. Well, Bowser, of course.

The episode (Mario and Joilet, episode 23, from 1999) is below – scroll to 13:33 to find out conclusively. 

If you're into video game character-related illusions, you'll love the Sonic X logo, which contains a great one.