SCA - General Information
SCA = Society for Creative Anachronism, a Medieval / Renaissance historical
recreation society that dresses in costume and holds feasts and tournaments and
classes on "Period" [650 AD - 1650 AD or thereabouts] crafts, costuming, sports,
etc. See http://www.sca.org/ for
more information about the SCA in general.
Washington State is part of the Kingdom of An Tir. Some of my favorite SCA events in the greater Western Washington area include Kent / Canterbury Fair in mid-August in the Shire of Wyewood, Ursulmas in late January in the Barony of Aquaterra, and Lionheart's tourney in mid-June in the Barony of Madrone. Canterbury Fair and Ursulmas are both demo events, meaning they are open to the public dressed in modern clothes, though the SCA participants will be in period-appropriate garb. All participants at tournaments such as Lionheart's are expected to be in at least some attempt at period appropriate clothing, though many groups have loaner garb called "Gold Key" available, especially if you arrange with the hosting group in advance to see if soemthing's available in your size.
In recent years I've also attended a few Kingdom level events, including Twelfth Night Coronation and May Crown Tourney. Both were fun and a different perspective than some of the smaller area events.
For more information about how I am personally involved in the SCA, see my SCA Personal page.