Overextension is a function where a nations starts to suffer from Unrest because of going beyond from the max provinces limit.
Overview[]
Once the player's country gains provinces above their max province limit, overextension kicks in and each new province gives unrest (ex. 24 total and 20 max, and 3% OE per province. You only get 12% total OE because 24-20 = 4.)
Overextension per province starts at a base value of 5% per province and is decreased with overextension reduction techs like Imperial Administration and Feudalism. Overextension could also be decreased by Easy mode on VIP servers.
Overextension helps keep monstrously large nations from forming. But it's deliberate function fails preventing people from successfully attempting it so by reducing poor taxes, using Rebel Suppression policies, researching Overextension Reduction techs, and Spamming Political Power to keep unrest down.
Controversy[]
Overextension gained controversy because of its immense buff from War Universalis 1 to War Universalis 2. Much of the player base disliked the feature in War Universalis 2's early release, but this controversy has calmed down as of 2020.