noun
free-to-play; non-paying; F2P
Used in gaming and online service contexts to describe a player who does not spend real money on virtual goods or premium features. Often contrasted with 課金者 (paying user).
See also: 課金
このゲームは無課金でも十分楽しめる。
You can fully enjoy this game even without spending money.
無課金プレイヤーは広告を見てアイテムをもらうことが多い。
Free-to-play players often get items by watching ads.
微課金 means spending only a small amount of money, whereas 無課金 means spending nothing at all.
Compound of 無 (mu, 'without') and 課金 (kakin, 'billing' or 'in-app purchase'). The term emerged with the rise of free-to-play mobile and social games.