If you've been playing Pokemon games since childhood, type advantages are probably burned into your brain, especially for the first 151 Pokemon, the ones currently featured in Pokemon GO. There are, however, a large number of types out there, and it can be a bit overwhelming for some players. That's not to mention, of course, that Pokemon GO is getting the game into the hands of people who would never have considered laying hands on a Gameboy or 3DS at all. This means a lot of people out there are flying their team flag proudly and would love to win some gym battles and represent their team, but keep getting stomped, and are probably wondering what's behind those "Super Effective!" and "It's not very effective..." messages they keep seeing in battle.
For those not already in the know, a handy chart has been prepared. Using information culled from current generation Pokemon games on the Nintendo 3DS, the type chart applies just as handily to the Pokemon living on your local streets and inside your smartphone. A super effective hit deals 1.2 times normal damage, and a not very effective hit only deals .8 times the normal damage in Pokemon GO, so savvy players could use type advantages and good reflexes to smoke much stronger Pokemon in the gyms. Even if a Pokemon's type doesn't line up right, catching Pokemon with the right types of moves and powering them up to diversify your arsenal can be just as effective. A good example may be certain flying types that can learn moves in the dragon, flying, normal, and fighting spectrums.
The chart may seem a bit complex at first glance, but it's really quite simple. Start in the middle. The elements and types to the left will deal extra damage against that type, while the ones found on the right will deal out hits that aren't very effective. Grass Pokemon, for example, will have a hard time with ice, poison, bug and fire types, while finding their footing against water, ground and rock types. They may seem arbitrary, but thinking carefully about them, some of the type weaknesses are quite logical. Bug Pokemon, for instance, have a hard time with flames, crushing rocks, and birds that would just as readily eat them as fight them, but don't have the mental capacity to suffer from psychic and dark attacks. Grass, of course, is bug food, so grass attacks won't make a bug type flinch much.