Ricochet

Ricochet is the phenomenon in which a moving projectile rebounds after impacting a surface, altering its trajectory and sometimes its energy. It is observed with bullets, arrows, stones, and other projectiles, across military, sports, and geology contexts.

The rebound results from the interaction of the projectile with the surface at the moment of impact. For a ricochet to occur, the projectile typically strikes at a shallow angle on a hard surface with insufficient energy to penetrate. The deflection is affected by the incidence angle, the surface’s hardness and roughness, the projectile’s shape, velocity, and spin, and whether the impact causes deformation or fragmentation.

Surfaces commonly involved include steel, concrete, wood, rock, and water. In water, a skipping effect can occur only at certain speeds and angles due to buoyancy and surface tension, and projectiles tend to lose energy quickly.

In practice, ricochets create safety hazards because trajectories are unpredictable and can travel long distances. They are a consideration in marksmanship, law enforcement, and military planning, and are generally mitigated by safety protocols such as avoiding firing at hard or angled surfaces and using appropriate ammunition. The term derives from the French word ricochet, referring to the rebound action.