The total cost of the biggest games now reportedly tops $1 billion

Game development costs can potentially reach $1 billion, when taking into account development, marketing, and promotion.

Last week, a UK government agency ruled against Microsoft's purchase of Activision Blizzard, on the grounds that it would harm competition. Now, after the 418-page report from the agency has been analyzed in detail, there's some fascinating details about game development costs.

Namely, as IGN points out, the CMA report details that some major publishers can spend north of $1 billion on making their biggest franchise games. The report reveals a major AAA game greenlit now might cost $200 million to develop alone, and it's revealed Call of Duty has already ballooned past this, reaching $300 million to develop one game alone.

In fact, one major publisher reveals in the report that they spent $660 million developing a single game, with marketing costs equating to nearly $550 million. This has taken the unnamed game well past $1 billion in total costs from the publisher, when everything was said and done.

The CMA's report draws a contrast to game development budgets from just five years ago, which were then estimated to be between $50 and $150 million for the biggest games around. Game development budgets have spiralled over the past five years, the CMA's new report has outlined, to the point where a total budget of $1 billion definitely isn't out of the question.

Elsewhere in the new report from the agency, the CMA said Microsoft would lose substantial money by making Call of Duty an Xbox exclusive. The agency effectively disagreed with Sony's concerns that Call of Duty as an Xbox console exclusive would be profitable for Microsoft.

Microsoft and Activision both said it would appeal the CMA's ruling against the potential acquisition in the near future.