Shield

A shield is a portable protective barrier carried by an individual, designed to intercept incoming weapons and projectiles and to provide cover. Throughout history, shields have enabled soldiers to advance and maneuver while gaining protection, and they remain in use in modern times by police and military units as well as in sport and ceremonial contexts.

Shields have varied in material and shape, including wood, leather, metal, and composites, often reinforced with metal rims or a boss. Common features include a hand grip or arm strap, and a central boss on many metal or reinforced wooden shields to deflect blows and enable punching during close combat. Shields may be circular, oval, rectangular, or curved, reflecting different fighting styles.

Historical examples include the Greek hoplon (aspis) used by hoplites with a full-body shield that encouraged the shield wall tactic; the Roman scutum a large curved shield; the Iberian buckler; the Celtic targe; the Viking round shield. In later periods, pavises provided portable cover for archers. In modern security, riot shields and ballistic shields are typically made of polycarbonate or layered composites and may be transparent.

In heraldry and symbolism, shields function as a surface for coats of arms, reflecting family status, allegiance, or achievement. The term shield also appears in phrases such as shield walls, which describe tactical formations.

Beyond personal use, shielding concepts appear in engineering and science, such as electromagnetic shielding to block interference, or radiation shielding in medical and industrial contexts. The term can also denote software or network measures that protect systems.