As we all know in the Pokemon universe, a Pokemon is capable of having either one or two types, which of course affects the types of moves that learns as it levels and grows. However there are a number of Pokemon who possess an abnormal amount of abilities from a type that they are not. Having noticed this, I have devised something that I like to call the ‘tri-type theory’, in which some Pokemon would theoretically be three types, rather than the maximum two. The third type is normally affiliated by some aspect of the Pokemon’s physical appearance, moves, or history, and as a result has associated moves at their disposal. One of the best examples for this theory would be Lugia.
In the games, Lugia is a Psychic/Flying Pokemon, which lives at the bottom of the ocean. However, its close association with Water (being a direct opposite of Ho-Oh, along with the title of ‘guardian of the seas’) would mean that its ‘third type’ would be Water, which makes sense considering its ability to learn all three Water-based HM moves, as well as its habitat. Other examples of tri-type Pokemon could include Charizard and Gyarados, which both share close association with Dragons, so theoretically could have Dragon as their third type.
As of Generation 3, the introduction of abilities further aids the theory of tri-type. Flygon for example, who is a Ground/Dragon, also wields the ability to fly, though does not is not part Flying. The advantage of the Flying type is granted to Flygon with the ability ‘Levitate’, which grants it immunity to Ground-type moves. Flygon’s previous evolution, Vibrava, along with several other Pokemon capable of flight (but are not of the flying type), also tend to have Levitate as their Ability. These Pokemon include Latias, Latios, Giratina, and Hydreigon. However there are other Pokemon like Beedrill, Dustox, Venomoth, and Volcarona (the last of which can actually learn the move Fly), who do not have this benefit. Rather, their ability is associated with something closer to their primary Bug type.
While the theory is aimed more toward the Pokemon games in themselves, there is a case in the Trading Card Game where Pokemon with three types exist. These are called the ‘Crystal Pokemon’, where the Pokemon is a colourless type, but one of the card’s abilities allows it to change its type to one of three. However in most cases, only one of the card’s types are actually associated with the Pokemon’s type (in these cases, the Pokemon only has one type, or the secondary type is one not associated with a TCG symbol). Some like Celebi and Lugia, have two of the three affiliated with it.
Despite the evidence scattered throughout the series as a whole, tri-typing is still only a theory, since the mechanics of the game prohibit an actual third type. And even though the use of the theory is to explore Pokemon in more depth, the use of the theory can be transferred to the games by a new player. If a new player looks at a Pokemon’s physical appearance, it’s possible to make good guesses of what moves that Pokemon can learn.