90 years from the date of creation for interest to vest a wait and see approach - look to see if it really does vest within 90 years (either get 21 years from lives in being OR 90 years from date of creation, whichever is longer); looks at what actually happens, not absurd hypotheticals if something violates RAP, the court will just fix the interest so that it does not violate Should include a RAp savings clause (indicate what happens if RAP is violated - mainly just an alternate beneficiary)