Sticker

"Hey, that's a sticker, isn't it?! Lucky you, picking up something so great."

- Kersti

Stickers are important elements in Paper Mario: Sticker Star. They serve as Mario's main method of attacking, and as such there are a wide variety of stickers to attack with. They are also used to solve puzzles and unlock pathways. Stickers were originally round-shaped, then changed to hexagonal before they became square-shaped in the final game. Additionally, Mystery Box stickers were planned as seen in artwork, but they do not appear in the final game.

Background
Stickers come from the Sticker Comet. Once every year, they rain down on the Mushroom Kingdom during the Sticker Festival. After Bowser accidentally shatters the Comet and scatters the Royal Stickers, Mario is forced to retrieve them with the help of Kersti, a sticker being who is the caretaker of the Sticker Comet. Along the way, stickers are used to solve puzzles and battle enemies.

Stickers can be found almost everywhere. Battle/item stickers are sorted into seven different categories by strength; Worn-Out, Normal, Shiny, Flashy, Big, Big Shiny, and Megaflash. They are sometimes dropped by enemies, found on walls, found in ? Blocks, bought at shops, etc. Collected stickers are kept in Mario's album, and each page in the album is 6-by-10 spaces (which can hold 15 small stickers in a 3x5 arrangement). Stickers can only be kept as long as there is space in the album, and certain stickers take up more room than others. In order to maximize usage of space, it may be necessary to rearrange stickers or even remove them. Pressing while looking at the sticker album will automatically re-arrange all stickers to maximize free space. This setup usually consists of two large stickers in a corner surrounded by smaller ones, though it varies depending on the size of the stickers collected.

The Sticker Album is grouped into different tabs: Stickers vary in size. The three different sizes stickers come in are:
 * Stickers - This section of the album holds all battle/item stickers and Thing stickers.
 * Things - While not technically stickers themselves, Things can be converted into Thing stickers at a shop in Decalburg or at Outlook Point (World 3-6).
 * Scraps - These are obtained from removing environmental objects from a Paperized scene or found on the floor. They can be re-pasted later to alter a new environment, either by simply filling voids or revealing new objects and paths. Some levels require the player to do this in real time, like Bowser's Snow Fort.
 * Small (1x1) takes up exactly 1 full square in the Album.
 * Medium (1.5x1.5) takes up 1 full square and 3 half squares in the Album.
 * Large (2x2) takes up 4 full squares in the Album.

Battle stickers
There are 96 battle stickers in the game.

Other stickers
These stickers are plot-related, and are only available in certain battles. These two stickers are not required for the Sticker Museum.

Things
"I have to tell you, I'm not familiar with that... thing. It's so rare to see something that's not flat!"

- Kersti

Things are objects that can be found within the game. They are named such because, unlike most of the denizens in the game, the items are not actually made out of either paper or similar material such as cardboard. There are a total of 64 things throughout the game, each with a different purpose. Mario finds them as actual objects, and they cannot be used in this state. Although they are not made out of paper, as noted before, they can be rendered into stickers by flinging them onto a special board at a Sling-a-Thing location. In addition, a specific Toad in Decalburg will sell things in a manner that is implied to be illegal. The player can then take the sticker and either paste it on the environment to cause events or use them in battle. Although not directly stated within the game, the player can execute Action Commands on most things by pressing (or in the case of the Cake, blowing into the microphone) in order to increase their effects. Mario can only carry one of each Thing at a time, whether in normal form or as a sticker. *Anything with a can only be accessed via a Secret Door.

Scraps
Scraps are pieces of the environment that can be removed and pasted into a certain location later on. They can either be obtained on their own or by peeling a certain piece of the environment off by paperizing, and can be placed back in their proper location with the same process. Removing something from the environment results in a void appearing in its place, which shows where the removed scrap or even another scrap is to go.

Upgrading
Throughout the game are hidden spots that can convert stickers into stronger stickers, referred to as Paperization Blocks. Occasionally, some stickers may produce hearts, coins, Five Coins, or 10 Coins. They are usually found above a hexagonal formation of flowers or tree stumps, and only support the smallest stickers. Below are the possible outcomes of an upgrade:

Hammer

 * North American website bio: "The plainest of many hammer stickers found out in the world still packs a punch, able to strike multiple ground-based foes at once."

Mushroom

 * North American website bio: "Bowser's minions can take a toll… but one of these will cure you of your woes in battle, and bring those HP back up."

Shell

 * North American website bio: "This sticker sends a Koopa shell flying at enemies on the ground. Watch them fall like bowling pins."

Jump

 * North American website bio: "Use Mario's signature jump move to stomp foes flat. Time it right to get a bunch of bonus jumps in—but watch out for spikes!"

Fire Flower

 * North American website bio: "Turn those paper-fied foes to ashes with a flurry of burning hot fireballs, and use expert timing to throw in a few extras."

Frog Suit

 * North American website bio: "Don the Frog Suit to send Mario jumping high up in the air. His increased airtime will help him avoid oncoming attacks."

Baahammer

 * North American website bio: "A hit from the Baa Hammer [sic] puts foes in a sleepytime mood, leaving them wide open to attack."

Trivia

 * If Kersti's sticker is used in any other battle apart from Bowser's, which is normally impossible without hacking, her dialogue does not appear. Instead, the game freezes at a white screen which does not dissipate unless a Thing sticker is used. Additionally, the usual benefits that the Kersti Sticker gives Mario, such as being shiny and having 5 Battle Slots, do not apply.
 * The Prima's Official Strategy Guide does not mention the ability to place small Thing stickers in the Paperization Blocks to gain 1 or 3 regular Leaf stickers or 3 Shiny Leaf Stickers.