Washington Revised Code Title 4. Civil Procedure § 4.22.070. Percentage of fault--Determination--Exception--Limitations

(1) In all actions involving fault of more than one entity, the trier of fact shall determine the percentage of the total fault which is attributable to every entity which caused the claimant's damages except entities immune from liability to the claimant under Title 51 RCW. The sum of the percentages of the total fault attributed to at-fault entities shall equal one hundred percent. The entities whose fault shall be determined include the claimant or person suffering personal injury or incurring property damage, defendants, third-party defendants, entities released by the claimant, entities with any other individual defense against the claimant, and entities immune from liability to the claimant, but shall not include those entities immune from liability to the claimant under Title 51 RCW. Judgment shall be entered against each defendant except those who have been released by the claimant or are immune from liability to the claimant or have prevailed on any other individual defense against the claimant in an amount which represents that party's proportionate share of the claimant's total damages. The liability of each defendant shall be several only and shall not be joint except:

(2) If a defendant is jointly and severally liable under one of the exceptions listed in subsections (1)(a) or (1)(b) of this section, such defendant's rights to contribution against another jointly and severally liable defendant, and the effect of settlement by either such defendant, shall be determined under RCW 4.22.040, 4.22.050, and 4.22.060.