The most crucial aspects to Arms lies within its very own namesake - the customizable weapon that are called Arms that every fighter can use and exchange. Arms come in all shapes, sizes, elements and types, and each have their own strength and weaknesses. Outside of the default Arms a player will gain, players can also participate in certain Game Modes to unlock new type of Arms and upgrade the ones they already own. By finding the best combination of Arms that work best on a given character and fighting style of such, a player will find great success while playing this game.