The [Traders & Barbarians][traders-barbarians] scenario “Barbarian Attack” uses a custom Development Card deck in place of the one used in the base game.
Note that this deck is not used when playing “Barbarian Attack” with [Cities & Knights][cities-knights]; instead, the Progress Card decks from that expansion is used in its place.
Appearance
As with all card decks, English and international cards are different in size, with English size using the bespoke “Catan size” (54mm x 80mm) cards and international sets using the mini European size cards (43mm x 67mm).
The card back for the development card deck has a clear indicator of which scenario it is associated with. The English 6th edition and 4th international edition has adopted a unified language-agnostic card back with a purple color scheme.
Gameplay
As with the base game, Development Cards are purchased. However, unlike their base game counterparts, cards are resolved once purchased, and placed into a discard pile afterwards
Should the Development Card deck be exhaused, the discard pile is shuffled to form a new Development Card deck.
Capture: This card, named Intrigue in the English 4th and 5th editions, allows a player to remove a Barbarian from the board and add it to their collection of captured Barbarians.
If there are no Barbarians on the board, this card is discarded, and a new one is drawn.
Knighthood: This card allows a player to place a [Knight][knight-ba] on any path adjacent to a Castle hex not currently occupied by another knight.
Swift Knight: This card, named Black Knight in the English 4th and 5th editions, allows a player to place a [Knight][knight-ba] on any unoccupied path on the board.
Treason: This card allows the player to take 2 gold from the supply, and move two Barbarians from two different hexes and place them on two different unconquered hexes.
If there are fewer than two Barbarians on the board, the needed barbarians are taken from the supply instead.