Missable content

Permanently missable content refers to items, equipment or other details that can be gotten at one point in the game, but can be missed permanently if the player does not obtain it before reaching a certain pint in the game, or before its location cannot be revisited again.

In Mario role-playing games, rare items and accessories are often more difficult to obtain past a certain point, and in some cases, missable content is rare to begin with (such as being available as rare drops from boss battles).

Luigi's Mansion
The player has only one chance to capture Speedy Spirits in dark rooms; if the player fails to catch one, it's gone forever, even during the blackout. The player has enough opportunities to capture a Gold Mouse as long as the room itself is dark. Should the player fail to catch one, they only need to exit and re-enter the room, and if there is a piece of cheese, to re-scan it with the Game Boy Horror again.

When sucking up a Portrait Ghost, the player must try to capture it in one attempt to collect all the pearls it drops. If the suction breaks in the middle of an attempt, the player may not be able to collect medium-sized or a large-sized pearl. If any pearls dropped from Ms. Petunia fall behind the bathtub in the bathroom on the second floor, the player will not be able to obtain them.

In the Boneyard is a lone plant in the garden. If the player waters it before fighting Bogmire, after defeating him, and after defeating Boolossus, it will grow and reward the player with lots of treasure. If the player fails to water it after defeating either boss, it will wither and die.

New Super Mario Bros. Wii
If the player loses eight lives when attempting a course, a Super Guide Block appears, permanently preventing the player from ever having shiny stars on their save file.

Super Mario RPG: Legend of the Seven Stars
The player has only one attempt to collect the Frog Coin inside a Surprise Box when Mario and Toad enter the castle in the Mushroom Kingdom for the first time (by jumping on Toad's head and climbing up to the Surprise Box).

Paper Mario
During Peach's segments, there are a few chances to use the special treasure chest to deposit items and Badges, the last opportunity being the segment after Chapter 6. Once Peach's segments are done, these items become unobtainable, even if there are items in Peach's possession.