If a condition precedent requires the performance of an act wrong of itself, the instrument containing it is so far void and the right cannot exist. If it requires the performance of an act not wrong of itself, but otherwise unlawful, the instrument takes effect and the condition is void.
Mont. Code Ann. § 70-1-403
Condition precedent requiring wrongful act
En
Official source: Montana Code Annotated (Montana Legislature). Reproduced from public-domain Montana statutes; confirm against the official source for the current text. Not legal advice.