The Cosmic Rock event is underway in Clash of Clans. This medal event is themed around the Halloween season, dubbed as Clash-O-Ween, like all the festivities Supercell released this month. Cosmic Rock features two event-exclusive currencies: Cosmic Shards and Rock Medals. The former is earned by performing Home Village multiplayer attacks and destroying buildings.The more Cosmic Shards you collect, the further you progress in the event's reward track, receiving items such as event-limited troops and Rock Medals. The latter are used to purchase exclusives that the event has brought to the Trader Shop.Since collecting Cosmic Shards and Rock Medals is the main goal in the Cosmic Rock event, you should do so while employing some tricks to collect as many of them as possible at the earliest. Read on to learn how this is done.Also read: How to three-star Cosmic Calamity challenge in Clash of ClansHow to collect Clash of Clans Cosmic Shards and Rock Medals like a proCosmic ShardsBesides Home Village multiplayer attacks, Cosmic Shards are earned by claiming them from the Boom Box decor situated in the Home Village. This building yields some Cosmic Shards periodically, just like Elixir and Gold Mines.You should also look out for giveaways conducted by COC content creators to grab free Cosmic Shards. One such giveaway is live. You can visit any COC content creator's social media profile and tap on the link captioned in the post announcing the giveaway to claim the freebies.Lastly, it's advised that you perform as many multiplayer attacks as possible during the Cosmic Rock event. It would be best if you three-star all your attacks, as it will reward you with lucrative Cosmic Shards. Avoid putting your Heroes on upgrade during the event to pull this off.Also read: Clash of Clans Cosmic scenery: Cost and designRock MedalsRock Medals are earned only via the event's reward track and giveaways conducted by the COC content creators. F2P players can earn only around 3,100 Rock Medals, while those with an Event Pass can earn about 5,500. That said, if you continue to collect Cosmic Shards even after completing the event's reward track, you will receive an extra 900 medals as a bonus.Also read: Clash of Clans Archer Hunter skin: Design and how to getMore articles related to Clash of Clans by Sportskeeda:October 2025 reward track: All rewards listedOctober 2025 event lineup: Seasonal challenges, medal event, and moreWhich is the best Equipment for Barbarian King?Ice Block Spell: Specialties, stats, and more