for keeps ------- 动真格的（非正式）

英文释义
(INFORMAL) An adverb phrase describing something done with deadly seriousness; permanently. (NOTE: often follows the verb "to play")

例句
While I simply play cards for amusement, my highly competitive brother always plays for keeps, and never laughs or smiles while he is playing.
我玩牌纯属为了娱乐，但是我的非常好胜的兄弟总爱动真格的，他打牌的时候从不带笑容，更不会笑出声。