Did Black Mirror: Metalhead come true?
Largely, yes. Black Mirror: Metalhead (2017) has a P(n) of 93% on Nearfi's P(n) Board, our estimate of the chance its future arrives within 20 years. Of its 4 tracked predictions, 1 have arrived and 2 are arriving. Its central premise, 'A ground robot identifies a human being as a target and pursues and kills them without a person authorising that attack', is expected within 50 years. The next prediction is estimated to arrive around 2029.
The hardware is further along than the episode's reputation suggests: four-legged robots are on sale, and armed ones have been shown by at least two militaries' suppliers. What is still missing is the part the episode runs on, a machine that picks a human target and pursues it with no person in the loop.
Read the review · 7.4/10 →
How this P(n) was calculated
P(n) is the chance that this work's future arrives within 20 years, by 2046. For each prediction we turn our estimate into a probability: arrived is 100%, diverged is 0%, and otherwise the low end of our 80% range counts as a 10% chance, the median year 50% and the high end 90%. Each prediction is weighted 1–5 by how pivotal it is to the story, and P(n) is the weighted average. P50 does the same by 2076. P(n), explained.
| Claim | Prediction · why this weight | Weight | Status · estimate | By 2046 | By 2076 |
|---|---|---|---|---|---|
| MH-1 | A commercially available four-legged robot can walk and run across rough ground, up slopes and over obstacles without a human steering each step. Supporting: the dog's mobility is what makes escape hard, but the episode's fear is aimed at what it does, not how it walks. |
3 | ARRIVED arrived 2020 | 100% | 100% |
| MH-2 | A four-legged robot carries a firearm and is used as a combat or security machine. Major: the dog's gun and shrapnel are how it kills, and the whole episode is about being hunted by one. |
4 | ARRIVING 2029 (2026–2036) | 100% | 100% |
| MH-3 | A ground robot identifies a human being as a target and pursues and kills them without a person authorising that attack. Core premise: the dog's autonomous hunt of Bella is the entire episode; nothing else would happen without it. |
5 | NEAR 2036 (2029–2050) | 79% | 100% |
| MH-4 | A legged robot can chase a person across country for hours at speeds a human cannot match, and recharge itself without help. Supporting: the dog's speed and stamina make Bella's escape a problem of endurance, but the plot turns on its weapons and its judgement. |
3 | ARRIVING 2030 (2027–2038) | 100% | 100% |
| P(n) = P20 = Σ(weight × chance by 2046) ÷ Σ weight = 13.9 ÷ 15 = 93% | |||||
| P50 = 15.0 ÷ 15 = 100% | |||||
Already here today (arrived 1, arriving ½, weighted): 43%.
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MH-1
A commercially available four-legged robot can walk and run across rough ground, up slopes and over obstacles without a human steering each step.
Weight 3/5 · Supporting: the dog's mobility is what makes escape hard, but the episode's fear is aimed at what it does, not how it walks.
Boston Dynamics put Spot on sale in June 2020 at US$74,500 for commercial use, and Chinese makers such as Unitree now sell larger quadrupeds. The real machines still fall over, misread glass and mirrors, and have to be told where to go. The walking is solved; the judgement is not. 12
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MH-2
A four-legged robot carries a firearm and is used as a combat or security machine.
Weight 4/5 · Major: the dog's gun and shrapnel are how it kills, and the whole episode is about being hunted by one.
Ghost Robotics and SWORD International showed a quadruped with a 6.5mm Creedmoor rifle at the US Army's annual convention in October 2021, and China displayed rifle-armed robot dogs at the Golden Dragon drills with Cambodia in May 2024. Both were reported as remote-controlled, and the Chinese weapons were walked, not fired, in front of journalists. Armed, fielded and used in combat is a step further. 345
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MH-3
A ground robot identifies a human being as a target and pursues and kills them without a person authorising that attack.
Weight 5/5 · Core premise: the dog's autonomous hunt of Bella is the entire episode; nothing else would happen without it.
No fielded ground machine is reported to do this. The US Defense Department's 2023 directive on autonomy in weapons does not ban autonomous systems that target people; it requires senior review, which can be waived, and asks for 'appropriate levels of human judgment'. The legal bar is a policy, not a treaty, and the technical gap is perception and judgement in clutter rather than mobility. The date is a judgement about doctrine as much as engineering. 678
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MH-4
A legged robot can chase a person across country for hours at speeds a human cannot match, and recharge itself without help.
Weight 3/5 · Supporting: the dog's speed and stamina make Bella's escape a problem of endurance, but the plot turns on its weapons and its judgement.
Boston Dynamics' 2019 spec sheet gave Spot a top speed of 1.6 m/s and about 90 minutes of runtime. Unitree lists its B2 at more than 6 m/s in special configurations, 4 to 6 hours per battery and optional autonomous charging. The speed is a lab-grade claim with a safety limit in practice, and autonomous charging is listed only as an option. 910
- FOR Boston Dynamics' Robot Dog Price and Availability. IEEE Spectrum, 2020-06-16. Spot went on sale to commercial buyers; the user guide lists holes, cliffs, slippery surfaces and glass as hazards.
- FOR Unitree B2. Unitree Robotics. Manufacturer page for a larger quadruped, with payload, endurance and speed figures; some functions need human operation.
- FOR Robot Dogs With Assault Rifles Unveiled at AUSA 2021 Convention. The Defense Post, 2021-10-13. A quadruped carrying SWORD International's rifle was shown in Washington; it was described as mainly remote-controlled.
- FOR China Shows off Robot 'Dogs of War' in Cambodia Drills. The Defense Post, 2024-05-16. Rifle-armed robot dogs appeared at the Golden Dragon 2024 opening; they were remote-controlled and only walked on leashes.
- AGAINST Ukraine's killer robots are showing how war is changing. RTE Brainstorm, 2026-05-01. Ukraine's armed ground robots are used in direct combat but are remotely operated, and they are wheeled or tracked rather than legged.
- CONTEXT Pentagon updates guidance for development, fielding and employment of autonomous weapon systems. DefenseScoop, 2023-01-25. The revised DoDD 3000.09 requires senior-level review and 'appropriate levels of human judgment' over the use of force.
- FOR Review of the 2023 US Policy on Autonomy in Weapons Systems. Human Rights Watch, 2023-02-14. The policy does not prohibit autonomous weapons that target people; senior review can be waived for urgent need, and the key terms are undefined.
- AGAINST Ukraine's killer robots are showing how war is changing. RTE Brainstorm, 2026-05-01. The author says today's armed ground robots in Ukraine are remotely operated, not fully autonomous, and calls for humans to stay in control.
- FOR Unitree B2. Unitree Robotics. Over 6 m/s in special configurations, 4 to 6 hours per battery, optional autonomous charging; a speed limit applies in practice.
- AGAINST Spot Robot Specifications. Boston Dynamics, 2020-05. Max speed 1.6 m/s, average runtime 90 minutes, recharge time 120 minutes: the first commercial quadruped was slower than a person running.
Ledger updated 5 Nov 2026. All works on the P(n) Board · Method