The Special World Finals 2021 Pin was rewarded to the champions of the World Finals.They will be available for purchase at a later date. The World Finals 2021 Player Pins could be collected via watching and interacting the World Finals 2021 on a special website created by Supercell.The Brawl-O-Ween Pins can be collected by buying all of the Brawl-O-Ween skins.The Retropolis Pins can be collected by buying all of Retropolis skins.
The Championship Challenge Pins could be obtained from completing the first stage from Championship Challenges.
They returned during Brawl-o-ween 2021 when the skin became available to purchase.
You can only use 3 Brawler Pins and 2 Player Pins in battles. They come in various rarities, and can be used in the team/friendly game chat or in battles as emotes. Pins are in-game cosmetics obtainable from purchasable packs, deals which appear in the shop, or from the Brawl Pass as exclusive Pins.