The Steam Summer Sale Weapons are limited availability vanity weapons originally released as part of a 10-day promotion on the Steam videogame platform in summer 2014.
The items became available on June 19th 2014 and could be obtained via ‘crafting’ badges on Steam out of trading cards, which gave the user a random chance to be awarded one of the items.
The weapons were not soulbound so it was not necessary to be a Steam user to get hold of them. They have since been added as drops in the Mad God Mayhem dungeon.
The promotion did not include a katana amongst the weapons, despite ninja having been in the game since October 2012.