Wash. Rev. Code § 11.103.020
The capacity required to create, amend, revoke, or add property to a revocable trust, or to direct the actions of the trustee of a revocable trust, is the same as that required to make a will.
RCW 11.103.020
Application- 2011 c 327 : "Except as otherwise provided in this act:
(1) This act applies to all trusts created before, on, or after January 1, 2012;
(2) This act applies to all judicial proceedings concerning trusts commenced on or after January 1, 2012;
(3) Any rule of construction or presumption provided in this act applies to trust instruments executed before January 1, 2012, unless there is a clear indication of a contrary intent in the terms of the trust;
(4) An action taken before January 1, 2012, is not affected by this act; and
(5) If a right is acquired, extinguished, or barred upon the expiration of a prescribed period that has commenced to run under any other statute before January 1, 2012, that statute continues to apply to the right even if it has been repealed or superseded." [2011 c 327 s 40.]
Effective date- 2011 c 327 : "This act takes effect January 1, 2012." [2011 c 327 s 41.]