A contingent interest is an interest which is uncertain, either as to the person who will enjoy it in possession or as to the event on which it will arise.
[1] A future interest is contingent where the person to whom or the event upon which it is limited to take effect in possession or become a vested estate is uncertain.
Caine v Payne, 86 App DC 404, 182 F2d 246, 20 ALR2d 823.
If the condition upon which a future interest depends is precedent, the interest is contingent; if the condition is subsequent, the interest is vested, subject to defeasance.
Anno: 131 ALR 712.