The Nuketown competitive map has been on many adverts for Activision's Call of Duty as a pre-order incentive, but it seems it's not available at all retailers.
But the map is only available at GAME, in the UK, according to ukvgdeals. This has also been confirmed by Activision.
In a statement to Eurogamer, the publisher said: GAME UK Exclusive for 'NUK3TOWN' content applies to physical or 'boxed' copies of Call of Duty Black Ops 3 Standard Edition on PS4, XB1 and PC only. Limited time only, while stocks last. 'NUK3TOWN' content is also available by ordering (or pre-ordering) the PS4 console bundle, the hardened and Juggernog Editions or through any digital orders/pre-orders. Actual platform availability and launch date(s) to be determined. Internet connection required.”
The site has also spotted that this period of exclusivity expires in Spring 2016, according to small print in the game's trailer.