- "Standard armor of the type worn by knights." - Ultimate Ghosts 'n Goblins description
Knight Armor (騎士の鎧), also known as Steel Armor (鋼の鎧 Hagane no Yoroi) and Silver Armor, is Arthur's standard armor. Except for Cannon Spike, Arthur wears this armor in all games he appeared, and in most it will break into pieces when hit, protecting him once. Without an armor, a single hit from the demon forces is lethal for him.
In Ultimate Ghosts 'n Goblins, the armor can withstand 2 hits and Arthur can use simple magic powers with it.
- Magic Power Lv 1
- Armor Vitality 2
- Max Durability 3
In Namco × Capcom and Marvel vs. Capcom 3, the armor will not fall even when hit multiple times. However, in Namco × Capcom it breaks in the opening scene and when overheated with magic. In Project X Zone and Marvel vs. Capcom 3, Arthur only loses his armor when he equips the Golden Armor or Emperor Armor, their magic overheating the current armor and making them blast out of him. Sometimes he also takes his armor for various reasons in Namco × Capcom and Project X Zone, most being comical.