1. What does it mean?
현질 combines 현금, cash, with the action suffix 질. It refers to using real money for game items, currency, characters, or other paid features, rather than obtaining everything through play.
Also written or said as hyeonjil
2. The nuance
It is informal and can sound critical or self-mocking. The term says money was spent, not whether the purchase was necessary, wise, or allowed through a particular seller.
3. Examples
“이번 달은 현질 안 하고 모은 재화만 쓸 거야.”
This month I'll use only saved in-game currency, without spending real money.
“친구가 새 의상을 현질해서 샀대.”
My friend said they paid real money for the new outfit.
Sources
Sinjoeo Korean Slang Dictionary
References support the meaning and usage. Example sentences are written for NoCapWiki.