leveling up; grinding for levels
Video game term for raising a character's level, either through normal play or repetitive grinding.
RPGではレベル上げが欠かせない。
Leveling up is essential in RPGs.
ボスに勝つために、しばらくレベル上げをした。
I spent some time grinding levels to beat the boss.
Compound of レベル (level) and 上げ (raising), from the verb 上げる (to raise).