For the most part they just make you open any bags, and they feel around. I have seen wands, but rarely used.
Washington law RCW 9.41.300 does state:
(2) Cities, towns, counties, and other municipalities may enact laws and ordinances:
(b) Restricting the possession of firearms in any stadium or convention center, operated by a city, town, county, or other municipality, except that such restrictions shall not apply to:
(i) Any pistol in the possession of a person licensed under RCW 9.41.070 or exempt from the licensing requirement by RCW 9.41.060; or
(ii) Any showing, demonstration, or lecture involving the exhibition of firearms.
Hope its some help, you'd have to see what the local laws are, but seems that they may be able to restrict the stadium if I'm reading it correctly.
You are LEGAL to cary concealed.
(except that such restrictions shall not apply to: RCW 9.41.070)
They may deny you entrance and you may file a lawsuit.
I have no dought that you will win because of WA's constitution.
SECTION 24 RIGHT TO BEAR ARMS. The right of the individual citizen to bear arms in defense of himself, or the state, shall not be impaired, but nothing in this section shall be construed as authorizing individuals or corporations to organize, maintain or employ an armed body of men.
there are very few places you can not carry.
all of them are listed in the RCW.
and to POINTEDLY answer your question.
PLACES YOU CAN AND CAN"T CARRY IN WA
section 2 subsection B
(2) Cities, towns, counties, and other municipalities may enact laws and ordinances:
(a) Restricting the discharge of firearms in any portion of their respective jurisdictions where there is a reasonable likelihood that humans, domestic animals, or property will be jeopardized. Such laws and ordinances shall not abridge the right of the individual guaranteed by Article I, section 24 of the state Constitution to bear arms in defense of self or others; and
(b) Restricting the possession of firearms in any stadium or convention center, operated by a city, town, county, or other municipality, except that such restrictions shall not apply to:
(i) Any pistol in the possession of a person licensed under RCW 9.41.070 or exempt from the licensing requirement by RCW 9.41.060;
you CAN.