Idiom 成語 11

不失不得 (bù shī bù dé) is not a very common fixed idiom in modern Mandarin, but it can be understood from its parts:

不失 = not lose / does not lose
不得 = does not gain / cannot obtain

English meaning:
“neither gain nor loss”
or
“no gain, no loss”
or more naturally: “it makes no difference” / “net neutral outcome”
Usage sense:
It describes a situation where something results in a neutral outcome—you don’t benefit, but you also don’t suffer a loss.
If you want, you can give me the sentence where you saw it, and I can fine-tune the meaning more precisely.