STAB and Battle Math Explanation

STAB stands for Same Type Attack Bonus. When a Pokemon uses a move that is the same type of one of its own types, the move's attack power is multiplied by 1.5. (The ability Adaptability, known by Eevee or by Porygon-Z by evolving a Porygon2 with Trace, multiplies same type moves by 2 instead of 1.5.)

Determining damage dealt by an attack is not that hard. You can figure out how much more damage it would do than normal if you follow a few simple steps:

-If STAB is applied (the move used is the same type as one of the Pokemon's types), multiply by 1.5. (If the Pokemon has Adaptability, multiply by 2 instead.)

-If the move is strong against one of the Pokemon's types, multiply by 2 for each type that is weak to the move.

-If the move is weak against one of the Pokemon's types, multiply by 0.5 for each type that is resistant to the move.

-If one of the Pokemon's types is immune to the move type, multiply by 0.

-If the Pokemon scores a critical hit, multiply by 2.

Now here are some examples to see how the damage piles up:

Magneton attacks Pelipper with Shock Wave.
Magneton is Electric/Steel type. Pelipper is Water/Flying type.

(1.5x) STAB - Shock Wave is Electric type
(2x) Electric moves are strong against the Water type.
(2x) Electric moves are strong against the Flying type.
(6x) Total

That makes 6x against Pelipper, or 12x if Shock Wave is a critical blow.

Now here's another example:

Magneton attacks Swampert with Shock Wave.
Magneton is Electric/Steel type. Swampert is Water/Ground type.

(1.5x) STAB - Shock Wave is Electric type
(2x) Electric moves are strong against the Water type.
(0x) Electric moves are nulled by the Ground type.
(0x) Total

Just one immunity nullifies the entire attack.

Now here's a few more examples:

Sceptile attacks Pelipper with Leaf Blade.
Sceptile is Grass type only. Pelipper is Water/Flying type.

(1.5x) STAB - Leaf Blade is Grass type.
(2x) Grass moves are strong against the Water type.
(0.5x) Grass moves are weak against the Flying type.
(1.5x) Total

The 2x and 0.5x here cancel each other out. But since Pelipper isn't completely resistant to Grass, if the Sceptile doesn't have a move super-effective against Pelipper, Leaf Blade is a great offensive move.

Gallade attacks Pelipper with Leaf Blade.
Gallade is Fighting/Psychic type. Pelipper is Water/Flying type.

(1x) No STAB - Leaf Blade is Grass type; Gallade isn't.
(2x) Grass moves are strong against the Water type.
(0.5x) Grass moves are weak against the Flying type.
(1x) Total

That's only 1x...There are better options in the arsenal. Psycho Cut for Gallade would be a better choice; at least there, STAB is applied.

Gallade attacks Swampert with Leaf Blade.
Gallade is Fighting/Psychic type. Swampert is Water/Ground type.

(1x) No STAB - Leaf Blade is Grass type; Gallade isn't.
(2x) Grass moves are strong against the Water type.
(2x) Grass moves are strong against the Ground type.
(4x) Total

Despite not having STAB, 4x is nothing to sneeze at. Besides, Grass is the only thing you can decently assail Swampert with (sheesh, Sceptile routinely kills Swampert), so this is a must.

Porygon-Z attacks Swampert with Tri Attack.
Porygon-Z is Normal type only. Swampert is Water/Ground type.
Additionally, Porygon-Z has Adaptability.

(2x) STAB - Tri Attack is Normal type, and Porygon-Z has Adaptability.
(1x) Normal moves are average against the Water type.
(1x) Normal moves are average against the Ground type.
(2x) Total

Tri Attack is well liked on Porygon-Z, as you can usually get at least a 2x. Against Pelipper, Thunderbolt is better, as you will get 4x.

Roserade attacks Vileplume with Grass Knot.
Roserade is Grass/Poison type. Vileplume is Grass/Poison type.

(1.5x) STAB - Grass Knot is Grass type.
(0.5x) Grass moves are weak against the Grass type.
(0.5x) Grass moves are weak against the Poison type.
(0.375x) Total.

This is a perfect example of what not to do, right next to the non-STAB variation of this, and complete immunity to types. For goodness sake, at least use Sludge Bomb or Extrasensory.

Guide by GizoidΩ/Bass