BERLIN—Acer today showed off a prototype gaming laptop with a hinge that lets it transform into a tablet.

The Predator Triton 900 is a rare fusion of the popular gaming laptop and 2-in-1 convertible laptop categories. However, by no means is it light or thin, and its hinge doesn't rotate 360 degrees the way a normal 2-in-1 would.

Instead, the hinge acts as a fulcrum, allowing the display to slide forward and cover the top of the keyboard. Acer CEO Jason Chen briefly demonstrated the prototype on stage here at IFA, although the company isn't saying when it will go on sale in the US or how much it might cost.

A rotating hinge isn't the Predator Triton's only unique feature. Two of the other most futuristic aspects of this machine are actually on the base, rather than the display. First, you'll find a mechanical keyboard. This is a rarity on a laptop, even if it does come on some of the most expensive gaming behemoths like Acer's own Predator Triton 700.

The other unique feature in the base is a touchpad that doubles as a 10-digit keypad. The number keys are virtual—they're superimposed on the touch screen using backlighting and touch-sensitive zones—and can be turned off if you don't need them.

Unfortunately, the closest we could get to the Predator Triton 900 prototype at IFA was in a glass case. Acer isn't letting people get their hands on it yet, nor is the company offering detailed information about what sort of graphics chip or CPU might be inside.

Gaming laptop makers have a history of showing off wild prototypes at tech trade shows. Last year at CES, Razer demonstrated a multi-screen laptop named Project Valerie, but it never went on sale. The fact that the Predator Triton 900 already has a marketing name bodes well for a more swift arrival on the market.