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no good; not serving its purpose; useless; broken
hopeless; wasted; in vain; purposeless
cannot; must not; not allowed
no!; stop!
neutral point; intersection owned by neither player at the end of a game
それは駄目だと思います。
I think that's no good.
駄目でもともとやってみよう。
Let's try even if it might fail.
駄目なら別の方法を考える。
If it doesn't work, I'll think of another way.