A Back Shield is a new item that appears in Kid Icarus: Uprising. It looks like a small, golden shield with a purple gem at the center of it that constantly floats behind Pit when he picks one up. As its name suggests, its primary function is to protect Pit from enemy attacks coming from behind, and will rotate accordingly with his movement. The Back Shield appears in both Solo and Together Mode. They sometimes can be found before or in an enemy arena or in Treasure Boxes, and they only appear during ground segments.
This floating shield appears behind you, defending you from attacks from the back. While it doesn't help when tackling enemies head-on, it can be a lifesaver in situation where you're suddenly surrounded.
In the Super Smash Bros. series
The Back Shield appears as an item in Super Smash Bros. for Nintendo 3DS and Wii U and Super Smash Bros. Ultimate. It serves a similar function from Uprising and blocks enemy attacks from behind. However, the wearer can still be grabbed if the opponent's range is long enough.
This durable, defensive shield comes to Smash Bros. from Kid Icarus: Uprising. If you pick it up, it will attach itself to you, protecting your back from most threats. It won't stop grabs or piercing attacks, however, and it only lasts so long before vanishing.
The Back Shield in use in Together Mode
The Back Shield in Super Smash Bros. for Wii U