Growing up I didn’t even know the name of the plastic construction sets of tubes that formed cascading ramps for marbles – I just knew they were super fun. Marble runs come in all shapes and sizes, and GraviTrax, engineered by German toy and game company Ravensburger, is not only one of the best I’ve encountered, it’s also the most cerebral.

GraviTrax is perfect for when your kids are ready to sit down and deduce a series of clever physics puzzles, and to encourage fun hands-on experimentation and STEM-based learning.

Modular Marbles

The primary keys to GraviTrax’s success are modular, hex-based pieces and removable ramps. Most marble runs include the ramp and the holes on the same molded plastic pieces, limiting your options for how the pieces can be fitted together. With GraviTrax, the ramps are separate from the hex-based platforms, instantly giving me far more freedom to building a near infinite variety of miniature roller coasters.

The hex-shaped platforms and height tiles fit neatly into the four-piece base plate, which keeps the full structure sturdy as well as providing a handy visual guide when following the construction and puzzle books. As someone who loves LEGO’s but mostly prefers following a guide rather than free-forming, I very much appreciated these pair of building booklets.

The first booklet provides nine step-by-step building instructions for sample tracks of increasing difficulty, starting from the most basic single track ramp to utilizing every single piece in a massive, three-track design of intersecting marble tracks. The second booklet offers a series of challenge puzzles in several different varieties, such as hiding where the ramps go, or trying to guess which color marble will finish first in an asymmetrical track.


A free app also exists that incorporates the same construction designs into a digital building book. I ended up preferring the intuitive design and interactive display of the app, though it was difficult to differentiate the two different height tile pieces.

The app has several neat features, including being able to build your own design digitally and test to see if the run can be completed successfully. At that point I worry about taking too much time away from the hands-on experience back to the screen, but it’s a nice to be able to save your own custom building instructions for the future.

Get the Ball Rolling

The Starter Set comes with everything you need to build an impressive multi-level design. The system supports up to three separate tracks and several unique pieces, such as the Magnetic Cannon that propels other marbles forward using kinetic energy.

Some of the simpler pieces were the most impressive. A two-to-one lane piece with a lever bumper shifts marbles onto different lanes, one after the other. It may not be as visually distinct as giant loops or bowls, but the results are impressive and fun. These kind of pieces encourage high levels of experimentation, as well as using applied knowledge of speed, gravity, and timing.

GravitraxWith dozens of height tiles, a variety of hex pieces, and several different ramp lengths, the Starter Set easily provides hours of entertainment.

Ravensburger also produces several add-on expansions that I was able to try, though I was less than impressed.  One expansion set simply adds more of the basic pieces, letting you build slightly bigger sets for nearly half the cost of the Starter Set. Smaller single-piece expansions run $10 each. They include unique pieces like the aforementioned Magnetic Cannon (if you wanted a second one), and the Hammer.

If you and your child really love the Starter Set it’s nice to have the option to expand with more pieces, but I didn’t find them necessary yet. None of the smaller box gimmick pieces felt like must-owns either, which is partially due to how complete the Starter Set feels.

The Rating

GraviTrax is listed as appropriate for ages 8+. The modular design makes it far more complex than standard brightly colored marble runs, though I do wish GraviTrax had a bit more color, rather than uniformly clinical whites and grays.

The Takeaway

While GraviTrax shouldn’t be your child’s first marble run, it can very well be their last. The 100+ piece Starter Set provides a solid mix of instructional building designs, puzzling challenges, and plenty of opportunity for free-form building. Once you and your family are ready to graduate to a more complex marble run you will get far more play time and educational value from GraviTrax than any other marble track system on the market.

This article was written by

Eric has been writing for over nine years with bylines at Dicebreaker, Pixelkin, Polygon, PC Gamer, Tabletop Gaming magazine, and more covering movies, TV shows, video games, tabletop games, and tech. He reviews and live streams D&D adventures every week on his YouTube channel. He also makes a mean tuna quesadilla.