Change move power

Principle

A move's power can be changed for two distinct reasons:

• From the move itself: the move recalculates its base power based on the context.
• From an external effect: an active effect applies a multiplier on the base power.

The two mechanisms operate at different levels: real_base_power returns the base power (absolute value), while base_power_multiplier returns a multiplier applied afterwards.

From the move

Some moves can change their power based on their own rules. For example, the move Acrobatics doubles its power if the user has no held item.

To handle this behavior, override the real_base_power method in the move's class.

Example: Acrobatics

# Get the real base power of the move (taking in account all parameter)
# @param user [PFM::PokemonBattler] user of the move
# @param target [PFM::PokemonBattler] target of the move
# @return [Numeric]
def real_base_power(user, target)
  return power * 2 if user.item_effect.is_a?(Battle::Effects::Item::Gems) && user.item_consumed
  return power * 2 unless user.hold_item?(user.battle_item_db_symbol)

  return super
end

• power is the base power defined in the move's data.
• The item_consumed check covers the case where a gem was consumed at the beginning of the turn.
• hold_item? checks if the user still holds an item -- if not, the power is doubled.
• super returns the unmodified base power if no condition is met.

From an effect

Some effects can modify a move's power via a multiplier. For example, the ability Technician multiplies by 1.5 the power of moves with 60 or less base power.

To handle this behavior, use the base_power_multiplier method in the effect's class.

Example: Technician

# Get the base power multiplier of this move
# @param user [PFM::PokemonBattler]
# @param target [PFM::PokemonBattler]
# @param move [Battle::Move]
# @return [Float]
def base_power_multiplier(user, target, move)
  return super if user != @target
  return super if move.power > 60

  return 1.5
end

• super returns the default multiplier (1.0) if the conditions are not met.
• The check uses move.power (base power) and not real_base_power (power after modifications).
• Returning 1.5 is a multiplier: the final power will be real_base_power * 1.5.

Conclusion

• Use real_base_power if the change depends on the move's own logic. Return the modified base power (Numeric).
• Use base_power_multiplier if the change depends on an external effect. Return a multiplier (Float).
• real_base_power defines the absolute power, base_power_multiplier applies a multiplicative factor on top.