From Hearts of Iron 4 Wiki
Jump to navigation Jump to search

A modifier provides an entity a bonus or penalty in related game mechanics and context. Almost any aspect of the game can be affected by modifiers.


Modifiers are attached to a large number of entities, such as national spirits, other ideas, generals' traits, weather conditions etc. But these modifiers only affect game mechanics when the entities are attached to something. For example the modifiers of all traits a certain general has apply to him, while the modifiers of snow or mud apply to any provinces affected by these weather conditions. The most common case is an idea applying its bonuses to a country. Countries, generals, provinces etc. are the places that are subsequently checked for applicable modifiers.

When multiple modifiers of the same kind are attached to a container, they get added.


The country is the largest container for modifiers. It feeds from the following sources:

  • country specific and general difficulty settings
  • autonomy level
  • ruling country leader
  • ruling ideology
  • faction
  • war support
  • stability
  • active (continuous) national focus
  • ideas
  • decisions
  • military attache
  • lack of consumer goods
  • state buildings
  • researched technologies
  • active country-scoped abilities

Unit leaders

This includes generals, field marshals and admirals

  • attack/defense/planning/logistics level
  • traits
  • active unit-leader-scoped abilities
  • field marshal (for generals)


The effects of each modifier as well as the containers they consult are implemented individually. Refer to the list of modifiers or the specific game mechanic for details on what a specific modifier does.