Does Pokemon Go take into account STAB in gym battles?

In the main series games, there is a concept of STAB (same type attack bonus), where a pokemon of a certain type will get an additional attack bonus (+50%) when using a move that has the same type. This bonus is in addition to any modifiers caused by the target pokemon's resistances.

For example, a Fire type pokemon using a Fire type move would do additional damage, compared to a non-Fire type pokemon using a Fire attack, or a Fire type using a non-Fire type attack.

Solution 1:

Yes, it does. But only at 1.25x. Here is the decoded protobuf file. In it is this:

Items {
  TemplateId: "BATTLE_SETTINGS"
  BattleSettings {
    RetargetSeconds: 0.5
    EnemyAttackInterval: 1.5
    AttackServerInterval: 5
    RoundDurationSeconds: 99
    BonusTimePerAllySeconds: 10
    MaximumAttackersPerBattle: 20
    SameTypeAttackBonusMultiplier: 1.25
    MaximumEnergy: 100
    EnergyDeltaPerHealthLost: 0.5
    DodgeDurationMs: 500
    MinimumPlayerLevel: 5
    SwapDurationMs: 1000
  }
}

Solution 2:

Since there has been posted proof now, the STAB modifier is indeed in the game, just not as high as it used to be in the other games.

The exact calculations are

• super effective: x1.25
• not very effective: x0.75
• STAB: x1.25