December's top game amid the slump was <em>Call of Duty: Black Ops II</em>.

December's top game amid the slump was Call of Duty: Black Ops II.

US retail sales of video games and gaming systems fell 22 per cent in December, capping a year of declining sales for the industry.

Research firm NPD Group said overall sales fell to $US3.21 billion from $US4.1 billion in December 2011.

NPD estimates sales of new game hardware, software and accessories account for about half of what consumers spend on gaming.

Sales of video games themselves, excluding PC titles, tumbled 26 per cent to $US1.54 billion. Sales of hardware — gaming systems such as the Xbox 360 and the Wii U — fell 20 per cent to $US1.07 billion.

Call of Duty: Black Ops II from Activision Blizzard was December's top game.

For all of 2012, total game sales dropped 22 per cent to $US13.26 billion.

AP