编辑“Modifiers”（章节）

=== Modifier Effects ===
There are three types of modifiers.
* ''add'' modifiers add/substracts a set amount of a resource or attribute to a scope
* ''mult'' modifiers increase or decrease the amount of a resource or attribute by a percentage
* ''reduction'' modifiers divide an amount of a resource or attribute by a set amount

These affect the resource or attribute amounts in different ways.  For example, if the cost, production, or upkeep of a certain resource is ''x'', then the actual amount of that resource will be:

''((x + (Sum of all '''''add''''' modifiers)) * (1 + (Sum of all '''''mult''''' modifiers))) * (1 - '''''reduction''''')''

Example:

''planet_buildings_minerals_cost_mult = 1'' would make all the buildings cost twice as much minerals.  So a '''Research Lab''' that normally costs 400 minerals would cost ''400 * (1 + '''1''') = 400 * 2 = 800'' minerals.

''planet_buildings_minerals_cost_add = 1'' would make all the buildings cost one mineral more.  So a '''Research Lab''' that normally costs 400 minerals would cost ''400 + '''1''' = 401'' minerals

''pop_growth_speed_reduction = 0.5'' would make a species grow half as fast.  If a species on planet has a base growth speed of 4, their final growth speed would be: 4 * (-1 * 0.5) = 4 * -0.5 = 2

There can be multiple modifiers effecting a single resource cost, production, or upkeep.  For instance, if the empire has a civic that applies ''planet_buildings_minerals_cost_mult = -0.1'', but the planet has a modifer that applies ''planet_buildings_minerals_cost_mult = 0.20'', then the buildings on that planet will cost 10% more: ''(400 * (1 + '''0.20''' + '''-0.1''') = 400 * (1.1) = 440'' minerals.

''Reduction'' modifiers have a larger effect than ''mult'' modifiers.  Let's say a species has a base growth speed of 3.  They have a trait with ''pop_growth_speed = 0.25'' increasing growth speed by 25%.  Their habitability on the planet gives them ''pop_growth_speed = -0.10''  The empire has a temporary modifier giving them ''pop_growth_speed_reduction = 0.25''  There final growth speed is: ''(3 * (1 + 0.25 + -0.1)) * (1 - 0.25) = (3 * 1.15) * 0.75 = 3.45 * 0.75 = 2.5875
A ''Reduction'' modifier of 1 will always result in 0, no matter what ''add'' or ''mult'' modifers are applied as well.

There could also be other modifiers in the hierarchy.  For instance, if the modifer on the planet was ''planet_structures_minerals_cost_mult = 0.20'', then districts on that planet would cost 20% more ''(500 * (1 + '''0.20''') = 500 * 1.2 = 600'' minerals, while the buildings would only be 10% more.  Since ''planet_structures'' is the parent of ''planet_buildings'', the buildings would be effected by both modifiers, but ''planet_districts'' would only be effected by the ''planet_structures_xxxx'' modifier on the planet.  Which modifiers gets applied to a resource depends on where it is in the Economic Category hierarchy, as well as where it is being applied.