The first game to be granted an R18+ adults only classification under new legislation will be Ninja Gaiden 3: Razor’s Edge on Wii U.
It's the first game to receive the adult's only rating, after it came into effect at the start of the year.
News first broke on Twitter, via Vooks, before being confirmed in a press release.
The PlayStation 3 and Xbox 360 version of Ninja Gaiden 3 was given the highest possible MA15+ rating when it was released in March, 2012.
However, the Wii U version is an enhanced port, and supposedly considerably more violent than the original release, prompting the classification board to restrict its sale to adults.
Director of the Classification Board Lesley O’Brien revealed that an R18+ rating had been selected because of "high impact bloody violence".
“Ninja Gaiden 3: Razor’s Edge contains violence that is high in impact because of its frequency, high definition graphics, and emphasis on blood effects,” said Ms O'Brien.
Had it been released last year with the added violence, before the introduction of an R18+ rating for video games, it should have been banned from sale.
It is illegal for retailers to sell R18+ games to people under 18.
By Ben Salter