Sid Eternal is a captivating game where players collect cards known as 'Sidian(s)' by defeating enemies like 'Irregular' during class and exploration. With over 1,000 Sidians to collect, players can enjoy a variety of strategies. Sidians come in five rarities, from 1 star to 5 stars, and can be leveled up by fusing identical cards. Enhance Sidian skills using specific materials for a competitive edge.

Dive into various engaging game modes like Dungeon, where players earn Sidians and materials, Dorm for nurturing Sidians, and Exploration for gathering items and materials while unraveling a unique story. Craft items in Atelier, explore Sidian details in the Library, team up with others in Circles for rewards, and summon special Sidians in Heroes Forest for powerful battle lineups. The Shop offers items and Sidian summons for enhancing gameplay.