They are mainly used for Red Coin Missions and Health Restoration.
Each Red Coin is worth 2 normal Coins and restore two units of Mario's health when collected.
Red Coin Missions
Red Coins appear in every course, usually they are in a fashion of collecting eight of them.
The missions are usually the fourth or fifth Star in each world.
|Bob-omb Battlefield||Find the 8 Red Coins|
|Whomp's Fortress||Red Coins on the Floating Isle|
|Jolly Roger Bay||Red Coins on the Ship Afloat|
|Cool, Cool Mountain||Frosty Slide for 8 Red Coins|
|Big Boo's Haunt||Seek the 8 Red Coins|
|Hazy Maze Cave||Elevate for 8 Red Coins|
|Lethal Lava Land||8-Coin Puzzle with 15 Pieces|
|Shifting Sand Land||Free Flying for 8 Red Coins|
|Dire, Dire Docks||Pole-Jumping for Red Coins|
|Snowman's Land||Shell Shreddin' for Red Coins (N64) / Red Coins in the House (DS)|
|Wet-Dry World||Go to Town for "the" Red Coins|
|Tall, Tall Mountain||Scary 'Shrooms, Red Coins|
|Tiny-Huge Island||Wiggler's Red Coins|
|Tick Tock Clock||Stop Time for Red Coins|
|Boom Boom's pass||Coins spread across a castle|
|Cap Switch Courses||Tower of the Wing Cap/? Switch|
|Cavern of the Metal Cap/Behind the Waterfall|
|Vanish Cap Under the Moat/The Secret Under the Moat|
|Bowser Courses||Bowser in the Dark World|
|Bowser in the Fire Sea|
|Bowser in the Sky|
|The Secret Aquarium|
|Wing Mario Over the Rainbow/Over the Rainbows|
Other Types of Coins
There are two other types of Coins:
- Regular Coins are worth one Coin and also refill 1 health when collected.
- Blue Coins
- Worth 5 regular Coins and also refills 5 health when collected.