A gun shield is a piece of armor designed to be mounted on a crew-served weapon such as a machine gun or artillery piece, or, more rarely, to be used with an assault rifle. During the trench warfare stage of World War I, shields with clearance for a rifle barrel were sometimes used by riflemen to more safely fire at targets in no-man's-land. Shields were sometimes also fitted to wheeled rigs to make them mobile.
— In-game description
The Sniper Shield is a gadget featured in Battlefield 1 for the Scout kit. The gadget is a placeable shield with a narrow peep hole to allow players behind it to safely engage targets with Sniper rifles or other weapons. The shield protects players from most gunfire, but not from explosives, gas, or fire. Similar to other placeable gadgets, it may be picked up and redeployed as needed.
Enemy players may still shoot and injure the player through the peep hole. Weapons such as K Bullets, Spiked Clubs, and Pickaxes can destroy a shield in three hits, and heavier weapons in a single hit. It also causes Anti-Tank Grenades to explode against it, similar to vehicles. Allies carrying a Repair Tool can repair the shield if damaged.