Stormtrooper armor was the standard armor worn by the stormtroopers of the Galactic Empire. A white plastoid composite worn over a black body glove, the armor represented some of the best in the Empire and was dreaded by rebel freedom fighters.
Following the Proclamation of the New Order, the Republic clone troopers became the first generation of Imperial stormtroopers. The clone stormtroopers kept using their Phase II clone trooper armor while enforcing the rule of the new regime. Early stormtrooper armor of an different design was worn by the «TK-troopers,» enlisted stormtroopers who were trained during the early months of the Age of the Empire. Eventually, a standard armor design for stormtroopers was settled upon, with their armor becoming a symbol of the Imperial Era.
In 9 BBY, the Stormtrooper armor of the soldiers stationed within the Fortress Inquisitorius on the moon Nur had become sturdy enough to take several hits from a lightsaber. As such, when Jedi Master Obi-Wan Kenobi arrived to rescue Leia Organa, it took several strikes from his lightsaber to strike down two troopers.
Stormtrooper armor exhibits minor aesthetic alterations over the course of the original trilogy. According to Pablo Hidalgo of the Lucasfilm Story Group, these differences stem from the production design of the films and do not reflect in-universe updates like the distinct phases of the clone troopers’ armor. Its stylized depiction in Star Wars Rebels likewise does not represent a separate in-universe model.