Robot Combat Enters the Ring: REK and UFB Launch Competing US Fighting Leagues

The concept of 'Real Steel'-style robot boxing is rapidly moving from science fiction to a competitive reality, with two different organizations announcing competing humanoid fighting events in the United States. This week, REK (Robot Embodied Kombat) announced a five-city US tour, while UFB (Ultimate Fighting Bots), revealed a partnership with robotics firm Unitree for its own event.

The announcements signal a new phase for the emerging sport, which pits human-piloted, bipedal robots against each other in a test of both machine durability and operator skill.

A Tale of Two Leagues

On November 7, REK founder @cixliv announced the "REK AMERICA" roadshow on X (formerly Twitter), describing it as a tour bringing humanoid robot fights to cities from "LA to NYC." The tour is scheduled for an aggressive timeline, starting in Los Angeles on November 11, followed by stops in Vegas, Austin, and Miami, before culminating in New York City on November 25.

Just days later, robotics company Unitree announced its own partnership with a new league, @UFBots. UFB, or Ultimate Fighting Bots, describes itself as "the world’s first robot combat league where humans pilot robots in real-time battles." Unitree will serve as the robotics partner for UFB's event in Los Angeles on November 15, placing it in direct competition with REK's tour stop in the same city.

The 'Real Steel' Control Scheme

This form of combat relies on a human-in-the-loop, but the two leagues are taking different approaches to the control scheme.

REK has been developing its system using VR headsets, allowing operators to "embody" the machines for a one-to-one, immersive experience. REK previously held what it called the "world's first VR-controlled humanoid robot fight event" in San Francisco. According to reports, that event at the Temple Night Club was a massive success, significantly overbooking the venue's 2,500-person capacity. It featured Twitch co-founder Justin Kan and UFC veteran Hyder Amil piloting Unitree G1 robots.

UFB, in contrast, appears to be targeting a more accessible, game-like experience. Its platform allows pilots to control the robots using traditional game console controllers or a keyboard, with battles accessible remotely via a web browser.

These events mark a significant evolution from earlier robot combat shows like BattleBots or Robot Wars. Those competitions focused on wheeled machines built for maximum destruction, whereas this new league tests the balance, agility, and motor control of bipedal humanoids.

From 'Shrimp' to 'Beast': The Hardware Hurdle

The most commonly used platform is the Unitree G1—a robot costing around $16,000 that REK's CTO, Amanda Watson, described as a "shrimp" that "can't hurt you" —the league is also working with much more formidable hardware.

In a recent thread, Watson detailed the challenges of working with the Unitree H1_2, Unitree's (previous) flagship model that is nearly 6 feet tall, weighs 154 lbs (70kg), and costs over $100,000.

Watson noted the H1_2 is a "beast" and that "the ground shakes when it walks." This power is precisely why REK is interested in it. "Unlike the Unitree G1, the H1_2 COULD hurt you," Watson wrote. "If it can hurt me, it can probably put some damage on another robot in the ring."

However, this power comes with significant engineering challenges:

• Legacy Support: The H1_2 is "getting phased out," and its support is "frozen in a less hand-holdy time."
• Motion Constraints: The robot has major limitations, including an inability to perform waist bends (it can only twist), forearm rotation, or head movement.
• Safety Hurdles: Deploying code to the H1_2 is described as "terrifying." Watson noted there is "no physical e-stop," only a serial port and a BLE remote with a "damp command."

These limitations highlight the stark difference between the older H1 series and Unitree's new H2, which features a 3-DOF waist and a 2-DOF articulated neck, among other improvements, specifically to solve these motion problems.

Sport, Spectacle, and a New Market

The sudden boom in robot fighting is not just a US phenomenon. Unitree previously partnered in a combat sports event in Hangzhou, China, using its G1 robots, while Shenzhen-based EngineAI is planning its own "Mecha King" tournament.

For hardware manufacturers, these high-profile events are a powerful publicity tool and a potential new business vertical. By partnering with leagues like UFB, Unitree positions its robots as the premier platform for this emerging sport, showcasing their durability and control to a wide new audience. If the "Real Steel" concept gains mainstream traction, it could open a significant new commercial market for these companies, separate from their long-term goals in industrial and home automation.

This move into entertainment leverages the same core teleoperation technology being developed for other purposes. Unitree, for instance, recently demonstrated an "Embodied Avatar" motion-capture suit which it explicitly labeled a "full-body data acquisition platform" for training robots to do household chores. While that system is aimed at solving the AI data bottleneck, the boxing demos included in the same announcement highlight a clear and perhaps more immediately commercial application: powering the next generation of high-stakes, human-piloted sport.