Wash. Rev. Code § 9A.16.100
(1) It is the policy of this state to protect children from assault and abuse and to encourage parents and their authorized agents to use methods of correction and restraint of children that are not dangerous to the children. However, the physical discipline of a child is not unlawful when it is reasonable and moderate and is inflicted by a parent or guardian for purposes of restraining or correcting the child. Any use of force on a child by any other person is unlawful unless it either:
(2) The following actions are presumed unreasonable when used to correct or restrain a child:
[ 2024 c 219 s 6; 1986 c 149 s 1.]