Star Coin

Star Coins are collectibles introduced in the New Super Mario Bros. series. They also appear in Mario and Donkey Kong: Minis on the Move and Mario Golf: World Tour. They are based on Dragon Coins from Super Mario World, even reusing the corresponding sound effect for collecting one from Super Mario World: Super Mario Advance 2.

New Super Mario Bros.
In New Super Mario Bros., there are three Star Coins in each of the eighty levels for a total of 240 Star Coins. Collecting a Star Coin adds 1,000 points to the player's score; some Star Coins may be hidden in areas that require power-ups such as the Mini Mushroom or the Blue Shell to access or collect them. In this game and subsequent appearances, collected Star Coins will show up as translucent on subsequent playthroughs of a level; a Star Coin does not count as collected until the player completes the level.

On the world map, the Touch Screen will display the total amount of Star Coins collected. Star Coins are used to open paths blocked by Star Coin Signs on the world map; each sign costs 5 Star Coins to open and allows the player to access Toad Houses or additional levels, which are represented with letters (e.g. World 1-A or World 5-B).

After completing the game at least once, a Blue Toad House will appear north of World 1-1 that sells 5 bonus Touch Screen backgrounds for 20 Star Coins each; the 5th background can be unlocked by opening every Toad House or spending all the Star Coins after collecting them. Collecting all 240 Star Coins will reward the player with a second star next to their save file, and "Complete" will appear on the Touch Screen next to the Star Coin counter; spending all the Star Coins will result in an "All Spent" message appearing next to the Star Coin symbol on the top screen in the world map reading "All Spent".

In the game's data, the collection sound effect is labelled as "SE_OBJ_GET_DRAGON_COIN", suggesting that they replaced Dragon Coins in the final game.

New Super Mario Bros. Wii
Star Coins also appear in New Super Mario Bros. Wii. Collecting one now adds 4,000 points to the player's total score. If the player collects all three Star Coins in a level, applause can be heard.

There are 231 Star Coins in total; collecting all Star Coins in a world will unlock a level in World 9 corresponding to that world number's (e.g. collecting the Star Coins in World 1 will unlock 9-1). Collecting all the Star Coins in the game, including the ones in World 9, will reward the player with a star on the File Select Screen. Star Coins can also optionally be used to buy hint movies at Peach's Castle.

New Super Mario Bros. 2
Star Coins appear again in New Super Mario Bros. 2. There are 219 Star Coins in total; as before, they can be used to open Star Coin Signs on the world map, leading to Toad Houses and additional levels.

In World Star, 90 Star Coins are required to access the actual levels; there is also a Yellow Toad House behind a Star Coin Sign that appears after all Star Coins have been found, and takes nine Star Coins to open. World Star itself does not have any Star Coins, but instead has similar Moon Coins; they cannot be spent, but count towards collecting all the Star Coins, and collecting them all rewards the player with a star on the File Select screen.

New Super Mario Bros. U
Star Coins appear once again in New Super Mario Bros. U, where they serve the same purpose as New Super Mario Bros. Wii; collecting all the Star Coins in each world unlocks a corresponding level in Superstar Road. There are a total of 246 Star Coins in the game.

Mario and Donkey Kong: Minis on the Move
Star Coins appear in the minigame Elevation Station in Mario and Donkey Kong: Minis on the Move. Collecting one adds 500 points to the player's score.

Mario Golf: World Tour
Star Coins appear in Mario Golf: World Tour and can be used to unlock new courses and playable characters. Players can earn them by clearing Star Coin challenges. These coins are also seen in the Extra level of the training games, where players are challenged to get the Star Coin with the ball while landing it as close to the pin as possible.

Super Smash Bros. series
In Super Smash Bros. for Nintendo 3DS / Wii U and Super Smash Bros. Ultimate, the coins produced from Mario's and Luigi's up special moves, Super Jump Punch, are Star Coins.

Puzzle & Dragons: Super Mario Bros. Edition
Star Coins appear in Puzzle & Dragons: Super Mario Bros. Edition as special Skill Items that raise the Skill levels of all forms of Mario except the 2.0 update forms, and all types of Hammer Bros., Coin Coffers, Thwomps and Whomps. They can be earned by opening up ? Blocks; winning them from the Lucky ? Blocks game at Toad Houses; randomly dropped by Koopa Troopas and Boom Boom; or from Big Thwomps and Big Whomps with a 10+ Combo attack. Other versions of Star Coins exist: Green Star Coins, Grand Star Coins and Grand Green Star Coins.

Mario & Sonic at the Rio 2016 Olympic Games
Star Coins appear in Golf Plus in the Nintendo 3DS version of Mario & Sonic at the Rio 2016 Olympic Games. In this event, Star Coins are used to score the event and decide the winner, and on most holes are earned by getting the ball into the hole in the fewest shots. They can also be earned by hitting ? Blocks, which will produce a random number of Star Coins that can be scored by reaching the hole in under the number of shots allowed for the hole.

Similar items
In Super Mario 3D Land, they are replaced by Star Medals, which have a slightly different appearance but essentially the same function. Star Medals were then replaced by Green Stars in Super Mario 3D World, still serving the same purpose.

Although Star Coins do not appear in Super Mario Galaxy 2, very similar items called Comet Medals appear.

New Super Mario Bros. 2

 * Instruction manual description: "Every course contains three of these. Once collected, they can be used to open new paths on the map screen."

New Super Mario Bros. U

 * Instruction manual description: "Each course contains three Star Coins. If you collect them all, something good might happen!"

Trivia

 * In Yoshi's Safari, the 10-Coins are large, circular coins that have an imprint of a Super Star, predating the Star Coins by 13 years.