Item sets are a feature introduced in the Mann-Conomy Update. Depending on the set, new attributes may apply to the wearer when all the items in a set are equipped, altering the role of the class slightly. Examples include increased damage resistance, an immunity to headshots, and silenced cloaking noises. There are currently thirty item sets; the five Polycount Pack contest winners, three Australian Christmas sets, eight Über Update sets, Dr. Grordbort's Victory Pack set, the Swashbuckler's Swag set, nine Very Scary Halloween Special sets, three Australian Christmas 2011 sets, and the hidden Eliminating The Impossible and Dual-Purpose Fruit sets.
The Polycount Pack item sets require players to have the set headwear equipped to activate the item set bonus. The Australian Christmas item sets do not require the corresponding headwear to activate the set bonus. The Über Update, Dr. Grordbort's Victory Pack, Swashbuckler's Swag, Eliminating the Impossible and Dual-Purpose Fruit sets, while they require their respective headwear and, if applicable, Miscellaneous item to complete the set, do not bestow a set bonus. All set headwear and misc. items can be crafted using four Refined Metal and a weapon from the set the desired headwear/misc. that the item belongs to (for example, 4 Refined Metal and a Soda Popper would make a Bonk Boy).
If a part of an item set is equipped, a list of items in the set as well as which are currently equipped appears when the item is inspected, either in the loadout menu or by other players. Unlike the others, the list for the Eliminating the Impossible and Dual-Purpose Fruit sets remain invisible until all items are worn together. If the entire set is equipped, any effects it provides are also listed.
List of item sets
- Added new attributes to the Hidden Detective set.