不動產法

一般規則（聯邦 / 多數州）

Common law: an interest is void when created if it might vest more than 21 years after every life in being has died. This stays the MBE default unless the question states a reform.

加州

Prob. Code § 21205: the interest is valid if it satisfies the common-law test, or if it actually vests or fails within 90 years. Under § 21220 a court reforms an interest that fails both tests.

一般規則（聯邦 / 多數州）

General law recognizes the fee simple determinable, which ends automatically, and the possibility of reverter, which lasts forever unless a marketable-title statute cuts it off.

加州

Civil Code § 885.020 abolished both. A would-be determinable fee is a fee simple subject to a condition subsequent. A would-be possibility of reverter is a power of termination, which must be exercised. The power expires 30 years after the instrument is recorded, unless a notice of preservation is recorded (§ 885.030).