There are so many little pieces of a game that don't make sense. Most players find it's easy to ignore theses coincidences claiming they're simply part of the gaming experience. Of course, Mario dies when he falls off a cliff, but he respawns at the beginning of the level because that is how the game is played. But what if it wasn’t that simple? What if there was a reason for those 'gameplay mechanics' that fit in with a game's lore?
A new fan theory addresses this by proposing that the citizens of the Mushroom Kingdom are actually immortal. This theory, started by Reddit user Demos1085, points out just how immortal Mario and the rest of the Mushroom Kingdom seem to be. According to Demos1085, an abundance of 1UP green mushrooms might be to blame. If a kingdom is flourishing with extra lives to throw around, maybe its citizens would get comfortable with the idea of immortality. Characters who are supposedly 'dead' already were likely born that way; Boos may not be ghosts, but rather, a species that simply look and act like ghosts.
While this might sound a little far fetched, the idea is backed up by various games. Take Mario Kart 64, for example. In this game, players who fall off the map's edge are not dashed to pieces on sharp rocks at the bottom. Instead, they are safely fished up by Lakitu and safely set back in place. No matter how deadly the fall looks, they are deposited safely ashore.
This theory is taken a step further in Paper Mario. As part of the main plot of the game, Mario is destroyed by Dimentio. Instead of a casket, Mario is sent to the Underwhere, an underworld place that video game characters are sent to after their games are ended. It could be that any characters who seem to fall to their demise are falling into the Underwhere or some other underground level. Mario would then have to travel back to the start of the level to climb out again, explaining why he begins every 'new life' at the start.
While it is not widely known, there is a piece of Mario lore that can be a little dark without this theory. According to the original Super Mario Bros. game manual, when Bowser took over the Mushroom Kingdom, he transformed all the citizens into "mere stones, bricks, and even field horse-hair plants." This is the explanation for the random floating brick blocks around each level; they're the transformed citizens of the Kingdom. Without context, Mario appears to be on a murder spree; however, if he knows they're immortal, Mario smashing bricks left and right could be because he is freeing them from their prison, knowing they'll respawn afterward.
Demos1085 branches off in the comments of their original post, suggesting that the theory could be tweaked a little. Instead of an abundance of green mushrooms leading to immortality, it could be that the characters are playing a game, and the players are only watching it. A character falling from the screen isn't dying, but rather jumping off stage in order to return later on stage right. This idea is backed up by Super Mario Bros 3, where the game starts up with curtains being drawn like a stage play. The game is set up that each of the characters are playing a part in a theater production, and therefore any falling, ground pounds or fireballs are just for show.
While it might seem a little silly to make up theories to explain why characters die in games (or why they don't), it does come in handy. Many games have unexplained backstories and little details that are easy to miss. While this immortal Mario theory is probably more likely to be game mechanics, it just goes to show that Mario fans are just as creative as ever.