It appears on the Peace negotiation screen when offering peace with a country under certain conditions. To annex a country, you must control all of its provinces, and the country must either be pagan or small enough that the total warscore value of its provinces is less than 100%. You may also annex a country of any size if it has just broken away from you in a war of independence. If accepted, the nation being annexed ceases to exist, and all its land becomes a part of the victor.
Depending on the situation in which it is demanded, varying amounts of Infamy can be acquired:
- Force-Annexing a country typically incurs 4 infamy per province (which may be reduced by a casus belli such as Imperialism). However, a one-province country incurs 8 infamy, no less than a two-province country.
- Force-Annexing a pagan country with the Colonial Conquest CB costs 0.8 infamy per province, regardless of size.
Annexing is perceived as an hostile act by the other countries which share religion with the country you have annexed. Therefore, the relations between you and these countries will drop. It is unknown by how much your relations drop, but it is estimated at 20 points.