The Paper Mario series is a RPG spinoff of the main games. Mario's adventures take place in a "paper" world. The first game, Paper Mario, was released for the Nintendo 64 in 2000 and was met with critical success. Thus, three more games in the series were born: Paper Mario: The Thousand-Year Door (GameCube, 2004), Super Paper Mario (Wii, 2008) and Paper Mario: Sticker Star (Nintendo 3DS, 2012).
Paper Mario is the game first game in the series for the Nintendo 64. Similar concepts from Super Mario RPG: Legend of the Seven Stars are prevalent. The story tells of a place in the sky, called Star Haven, where wish-granting stars lived. When a person makes a wish, they used the Power of the Star Rod to make it happen. One day, Bowser broke into Star Haven and stole the Star Rod from the Star Spirits and plans to make himself invincible. Back in the Mushroom Kingdom, Mario and Luigi have received an invitation to Princess Peach's party. They accept, and without hestitation, proceed to the party. Once there, Mario meets up with Peach, however, Bowser breaks in and the two get into a scuffle, Bowser being the victor. Mario is thrown out of the building, supposedly "dead", however the remaining power of the Star Spirits manage to revive him and they beckon for him to meet them at Shooting Star Summit. It is there that Mario promises to save the Star Spirits from their captors and rid the Mushroom Kingdom of Bowser and save Princess Peach.
Like Super Mario RPG, Mario befriends "partners" as he progresses through the story. They assist him in the game, such as using Goombario to provide information on places and characters or using Bow to go invisible. In combat, partners can be used to attack enemies, or provide Mario with a beneficial buff.
The game uses a turn-based combat system in order to fight enemies. Every turn, Mario has several options available to him: Jump, Hammer, Star Power, Items, and Tactics. Combat ends when all enemies have been defeated (or other under special circumstances). Mario uses HP (Health Points, life bar) and FP (Flower Points, used for special attacks) in combat. When Mario defeats a level-appropriate enemy, he earns Star Points. Once he earns 100 Star Points, he "levels up", and the player can choose whether to increase Mario's HP, FP, or BP (Badge Points, used for equipping badges).
Mario has the ability to equip badges, providing him with benefits, such as increasing attack power for his jump, or letting him use an extra item in battle. Each badge has an amount of points needed to be equipped.
The second game in the series, Paper Mario: The Thousand Year Door, was released for the GameCube in 2004. The story goes that there was a town that was filled with happy people. Eventually, a cataclysm struck the town, and when all hope was lost, the town began to sink into the ground. The story closes as Princess Peach comes into view in a strange town. She meets a mysterious vendor who offers her a magical box, the box opens up and a bright light shines from it. Mario and Luigi are at their house when the mail carrier delivers a letter addressed to Mario. Peach explains that she came upon a mysterious treasure map and she's going to go after it. Mario sets sail and arrives at Rogueport. When he first arrives, a female Goomba named Goombella is being harassed by members of the X-Nauts. Mario saves her, and she becomes his partner. They eventually meet her professor, Professor Frankly and they embark on a quest to find the Thousand Year Door at the bottom of the Rogueport sewers.
Like the previous game, combat is turn-based.
The third game in the series, Super Paper Mario, was released for the Wii in 2008. One of the biggest features in this game is Mario's ability to change from 2-D to 3-D at the push of a button. Instead of turn-based, combat is now in real time, with Mario being able to defeat enemies right on the field. For the first time in the series, Luigi, Bowser, and Peach are playable characters each with their own abilities.
The fourth game in the series, Paper Mario: Sticker Star was released for the Nintendo 3DS in 2012. The game provided new combat experience, Mario's attacks being fueled through the use of "stickers" acquired through various means. Special stickers could be acquired which would help Mario travel through each area.
The fifth game in the series, Paper Mario: Color Splash was released for the Wii U in 2016. Similar to Sticker Star, Mario's attacks were powered by having a "deck of cards" with special cards being necessary to defeat bosses and finishing certain levels. A new mechanic introduced finds Mario using Huey (a paint bucket) to paint with. Using this paint, the player could color in their cards to increase the effect from it. In addition, the the open world, the player could color in certain areas of the landscape such as grass and fences. When an object has been completely filled in, the player can be rewarded with coins and cards.