House rule: Category Upgrade
(Rule)Description: "Conversely, if players wish to add more colour and variety to their armies then they may wish to employ more of these spectacular units. If both players agree beforehand, Dogs of War units can be included as Special unit choices as well as Rare ones"
Warhammer Armies: Dark Elves (page 25)
Warhammer Armies: Skaven (page 41)
Warhammer Armies: Vampire Counts (page 61)