Offers of settlement shall be served on the adverse party in the manner prescribed by applicable court rules at least ten days prior to trial. Offers of settlement shall not be served until thirty days after the completion of the service and filing of the summons and complaint. Offers of settlement shall not be filed or communicated to the trier of the fact until after judgment, at which time a copy of said offer of settlement shall be filed for the purposes of determining attorneys' fees as set forth in RCW
4.84.250.