ingenious trick; clever scheme; good idea
Refers to a particularly clever or ingenious plan, often with a nuance of cunning or resourcefulness. Can be used in both positive and slightly scheming contexts.
彼は妙計を思いついて、難局を乗り切った。
He came up with a clever scheme and overcame the difficult situation.
それは妙計だね。
That's a good idea.
Compound of 妙 (myō, 'strange, clever') and 計 (kei, 'plan, scheme'). The exact historical derivation is uncertain, but the kanji combination directly conveys the meaning of a clever or ingenious plan.