Humanoid robot fighting: the REK league, its robots, rules and events

What REK is

REK is a commercial league from San Francisco in which humanoid robots fight each other in full contact. The company behind it, REK Inc., was founded in 2025 by Cix Liv, a VR entrepreneur (SF Chronicle, SF Standard). Most outlets expand the name as Robot Entertainment Kombat. Since 2026 the league has had its own venue at 1415 Van Ness Avenue in San Francisco, the REK Arena.

What makes REK different from classic robot wars is the hardware: these are not purpose-built combat machines but off-the-shelf humanoids that are also sold for research and education, mainly the Unitree G1 and the EngineAI T800. That is why the topic belongs in a robot catalogue: every fight is a public stress test of robots you can buy.

On 15 October 2026 REK's own site counted 15 events in 9 cities. It does not publish fight-by-fight results. We collect them, with a source for every row, on a separate page: “Humanoid robot fight results”.

How the robots are controlled

The fighters are not autonomous. A human pilot steers every punch and kick in real time, with a VR headset (Meta Quest) or a gamepad; at the Deathmatch in October 2026 an eyewitness saw wireless gamepads. On board, a trained balance system keeps the robot upright, and REK combines the pilot's input with trained motion patterns to make punches cleaner, according to its technology partner Reflex Arc. Reflex Arc also works on the delay between pilot and robot, the simulator and matchmaking.

This split matters for anyone judging the robots. A fall is usually not a "decision" by the robot but the limit of what its balance controller can absorb. According to Cix Liv, quoted by Gizmodo, the robot's head is cosmetic and has no vision, and a motor overload triggers a software emergency stop.

Rules: rounds, scoring and knockouts

REK has published a detailed rulebook (rek.com/rules, undated, retrieved 15 October 2026). Its main points:

Two caveats. First, the rulebook is not linked from REK's menu and describes unarmed robots, which does not fit the bladed Deathmatch; it may be a target rather than the rules every event used. Second, earlier formats differed: REK 1 in February 2026 was fought over five 60-second rounds with a human referee, according to Rest of World.

There are no weight classes. In practice REK has paired identical models, G1 against G1 and T800 against T800, which works as a weight class in all but name: a T800 weighs more than twice as much as a G1.

Every REK event so far

Dates and venues as listed by REK on rek.com/fights; audience figures only where a source gives one. "Winner" is the pilot REK names for the event.

Hiroyuki Osone is so far the only pilot REK names as the winner of two events. According to Reflex Arc he qualified for REK 2 through the simulator, from Japan.

Human against robot, and the California warning

On 18 September 2026 the influencer Frankie LaPenna fought three robots in a row: a Unitree G1 and then two modified T800s, called "Terminator" and "Predator" (Fox News). He wore body armour and shin guards and injured his hand. Who won is disputed: REK and SFGATE describe two wins out of three for the human, other outlets describe a win for the robots.

The fight had a legal sequel. The California State Athletic Commission sent REK a cease-and-desist letter: boxing or MMA contests "involving any human" need the commission's approval, and the letter cites the state's Business and Professions Code, under which a violation is a misdemeanor (Tom's Hardware). According to SFGATE the letter is dated 23 September 2026. Robot-only fights are not covered by the order.

The Deathmatch with blades

On 9 October 2026 REK held what it billed as the first humanoid weapon fight: three bouts, including a G1 bout with weapons, a T800 bout and the main event between two large robots called Rektile and T-REK. According to the SF Standard the blades were 10 to 20 inches of hardened AR500 steel, designed by REK's lead hardware engineer; about 100 people paid $69 a ticket. A camera lens was pierced and the cage panels were gouged.

For the robots, blades change the engineering problem. A punch loads the arm joints and the balance controller for a fraction of a second; a blade that sticks in a cage panel or in the opponent turns into a lever on the shoulder. This is one reason why we record such modifications separately, with sources, in our “Humanoid robot fight results”.

The robots in the ring

Sources: Unitree and EngineAI, retrieved 15 October 2026; EngineAI's page is not consistent on degrees of freedom and battery life.

The table explains a lot about the fights. The reference robot in REK's rulebook (132 cm, 35 kg, 29 joints, 120 Nm at the knee) matches the research version, the Unitree G1 EDU, not the base G1 with 90 Nm. The T800 has almost four times the peak joint torque of a G1 EDU knee and more than twice the mass, which is why the two do not fight each other. REK has also used the Unitree H1 for early teleoperation tests, and its shop lists an EngineAI PM01 in a "Battle Born Edition", described as heavily used in combat.

Try it yourself: the REK simulator

REK offers a free simulator with the same controls as the real robots, for keyboard, controller or VR, with a modified G1 and a T800 as starter robots. On 15 October 2026 its Steam page showed "coming soon"; minimum requirements are listed for Windows 10/11 and Linux (8 GB RAM, a GTX 1050 class graphics card). According to Reflex Arc the simulator also runs on Meta Quest in an early alpha, and the first championship had 3,670 matches. REK itself counts more than 20,000 simulator fights in 65 countries. Top players can qualify to pilot real robots, which is how Hiroyuki Osone reached REK 2.

Other humanoid fighting leagues

REK is not alone, and the Chinese leagues are larger:

• URKL (Ultimate Robot Knock-out Legend), run by EngineAI itself: 32 finalist teams on standardised T800 robots, start 16 July 2026 in Shenzhen, prize 10 million yuan according to the Shenzhen government.
• CMG Mecha Fighting Series: state broadcaster CMG's tournament with four Unitree G1 robots in Hangzhou on 25 May 2025, three rounds of two minutes, a punch worth 1 point and a kick 3 (Henan provincial government).
• ARC in Singapore: a fight night on 7 October 2026 with G1 and T800 robots and pilots in motion-capture suits (Humanoids Daily).

In Europe we found no comparable league on 15 October 2026. What exists here, what fight-capable robots cost in Europe and which rules apply is on our page “Humanoid robot fighting in Europe”.

What the fights say about the robots

The fights are entertainment, but they also show things that spec sheets do not: how often a robot falls, whether it gets up unaided within ten seconds, how long it lasts on one battery and how quickly it can be repaired. REK's rulebook allows one battery swap per fight, although a fight lasts six minutes and Unitree gives the G1 about two hours: the manufacturer's figure describes normal operation, and constant full load drains a battery and heats the motors much faster. If you are considering a humanoid for shows or trade fairs, our guide “Renting a Humanoid Robot for an Event” covers what is realistic in Poland, and the current prices are on the model pages in humanoid robots.