Type weaknesses and strengths stack, which means that you can cause as much as quadruple damage, or reduce incoming damage to just a quarter of the standard amount. Having two types means they'll have more strengths, but also more gaps in their defenses. If a Pokemon has a dual type, it'll have to consider the strengths and weaknesses for both of its types. The STAB bonus is a 1.5x bonus multiplyer on the move's effectiveness - which stacks with things like type weaknesses, which can in turn lead to truly devastating one-hit KO moves - if you play your battle right. Basically, this is what happens when your Pokemon uses a move that's also the same type as the Pokemon itself - they get a damage bonus. STAB is a term cooked up by the Pokemon fanbase that's short for Same Type Attack Bonus. There's three in particular we should touch on: About STAB, the Same Attack Type Bonus

Some Pokemon are even entirely invulnerable to moves of certain types. The same is true of Resistance - so in return, Fire really isnвЂ™t very effective against Water. But Fire is vulnerable to Water-type Pokemon, which can douse those flames. For instance, a Fire-type Pokemon can burn Grass-type Pokemon to the ground and melt Ice-type Pokemon likewise - meaning they do more damage to those types. In battle, this manifests itself as strengths and weaknesses. That means when youвЂ™re learning and changing a PokemonвЂ™s moves, youвЂ™ll want to consider type coverage, thinking about what sort of damage they can do. Similarly, every single Pokemon move in the game is tagged with an associated element and type. Some Pokemon can hold dual types - so for instance the butterfly-like Pokemon Beautifly is a dual Bug and Flying type. Magikarp, a flopping fish, is of course a water-type. These are pretty obvious - so Machop, the karate-chopping Pokemon, is Fighting type. Every single Pokemon has either one or two вЂtypesвЂ™ assigned to it. Watch on YouTube Understanding Pokemon Type Strengths, Weaknesses, and STAB

Pokemon type chart