Game Theory: How DEADLY is Sonic's Speed?

MatPat reflects on doing a Sonic episode five years ago and humorously revisits internet culture from that era. He introduces the channel's growth from 50,000 to 10 million subscribers.

Dominic, a Make a Wish Foundation member and internet personality from a previous Mario episode, requested a theory about Sonic's running ability physics.

If Sonic runs so fast, what happens to his legs? Wouldn't they wear out and get hurt?

Determine whether Sonic would survive his primary game mechanic of running at high speeds or develop arthritis after just the first level.

Running puts significant stress on the body, particularly on knees due to the constant pounding impact on joints.

• Knees are hinge joints made of three bones: femur (thigh bone), patella (kneecap), and tibia (shin) • Two types of cartilage protect the joints: hyaline cartilage covering bone articulation points and fibrocartilage providing padding • Cartilage does not regenerate in the body

Repeated stress could cause osteoarthritis, manifesting as stiffness, bone grinding, pain, and loss of mobility.

To calculate damage, MatPat needed Sonic's official weight and speeds. He treated Sonic as human-like rather than as an actual hedgehog for realistic joint mechanics.

Research from Southern Methodist University's Locomotor Performance Lab shows running force increases linearly with speed: 2.32 times body weight at 5 meters per second and 4.64 times body weight at 10 meters per second.

• Official weight: 35 kilograms (77 pounds) • Modern Sonic height: 3 feet 3 inches • Classic Sonic height: 2 feet 6 inches

Using pixel-to-centimeter ratios across Sonic 1, Sonic 2, and Sonic Mania: lowest speed is 7.13 meters per second (16 mph) for short Sonic in Sonic 1; fastest is 24.8 meters per second (55.4 mph) for tall Sonic in Sonic 2.

• Running forces range from 115 to 402 Newtons per leg • Even Usain Bolt exerts 440 Newtons, more than Sonic's maximum force • Sonic is light enough that his impact forces are relatively modest

Multiple studies from NPR and Runner's World show that running does not increase osteoarthritis risk. Runners have no more risk than non-runners.

A cross-sectional study of nearly 75,000 runners found no evidence that running increases osteoarthritis risk, even for marathon participants.

Cartilage does not wear away from running; it actually gets stronger when used regularly.

Sonic's running would not damage his health at all. The traditional warning about running damaging joints is a myth.

Although running doesn't damage Sonic, the way he stops is a different story. Sonic stops almost instantly by digging his heels in.

Stopping involves energy transfer. Sonic must lose all his kinetic energy rapidly using the equation kinetic energy equals one half times mass times velocity squared.

• Sonic's mass (35 kg) limits total kinetic energy despite high speeds • Stopping distance varies across games: from under 0.5 meters in Sonic 2 to 6.23 meters in Sonic Mania • Force equals energy divided by distance

MatPat calculated all possible scenarios across three games, two Sonic heights, and various speed boosters to determine the range of stopping forces.

Stopping forces ranged from 641 Newtons for short Sonic in Sonic 2 to 2,395 Newtons for tall Sonic in Sonic 2.

• 1,000 Newtons is equivalent to an adult's average bite force • 2,312 Newtons can tear an ACL (anterior cruciate ligament) • Breaking a tibia requires approximately 4,000 Newtons • At 2,395 Newtons, Sonic could only tear his ACL under specific angles

Sonic's stopping forces are insufficient to break bones. In most cases, he is completely fine.

The game designers made Sonic light enough, slow enough, and gave him sufficient stopping distance to remain safe during gameplay.

What if Sonic truly lives up to his theme song claim of rolling around at the speed of sound?

• Stopping distance at the speed of sound: approximately 69 meters • Stopping force: 29,842 Newtons—over 30,000 Newtons

A force of 29,842 Newtons is more than enough to shatter most bones in Sonic's body.

• If Sonic lived up to the speed of sound claim, he would be completely debilitated every time he tried to stop • Either Sonic destroys his body when firing up top speed, or Sonic must be slow • The video games present a compromise: Sonic's actual speeds are manageable and safe