• 2 doz. cupcakes
• Tea lights
• 2 doz lei
• 2 doz gift bags
• 12 feather boas
• 12 pirate swords
• 2 gal milk
• Birthday banner
• 2 packs juice boxes
• 5 pizzas
• 12 assorted party crowns
• 12 pink tiaras

As the children come into the party room they see the treasure box by the door overflowing with odd vests, second-hand dresses, scarves, hats, helmets, shields, tutus, capes (of course), foam swords, and they don these things, perhaps serially-changing from knight to ballerina to carpenter 

Seamlessly 

Because they are children 

And this is their kingdom.