Robo styles distinguish between robos of the same model. There are several robo styles, each of which have certain advantages and disadvantages. These styles, like the charge attack, are unique to each robo.
Normal style robos are subject to the advantages and disadvantages of their series, but have no alterations that separate them from other robos of their model. Because of this they could be referred to as the "jacks of all trades, masters of none". This style has appeared in all titles except for Custom Robo Arena.
Speed style robos are made with lighter armor. As such, they receive boosts in movement speed, aerial speed, or both. In order to compensate for this boost in speed, these robos generally lose armor and endurance. This style has appeared in all games.
Armor style robos are made with heavier armor plating. This gives them higher defense and endurance at the expense of lower mobility. This style has appeared in all games.
Power style robos are made with armor that increases the strength of all parts. However, these robos lose out on either defense or mobility (or sometimes both). This style has appeared in Custom Robo V2, Custom Robo GX, and Custom Robo Arena.
Jump style robos are made with more aerodynamic armor. As such, they receive higher stats in aerial mobility. They generally lose out on defense, however. This class only existed in Custom Robo V2 and was eventually merged with the Speed style.
A style distinct from the other three styles. Usually incorporates multiple styles. Most Illegal robos are of this subcategory. This style has appeared since Custom Robo GX.