These are the options for the Single Player Campaign in EU-4:
Contents
Handicap[edit]
Alongside the difficulty setting, you can assign penalties (handicaps) or bonuses to yourself or to the AI. If you choose to favor the Player, the AI will be assigned various penalties, while the player receives several bonuses, making it easier for you to win. If you choose AI, then your country will suffer various penalty modifiers while the AI countries will receive bonuses, making the game harder. When set Handicap to None, you and the AI are on an even playing field.
AI Difficulty[edit]
Set to Easy, Normal or Hard. This changes the overall difficulty and the aggressiveness of the AI towards the player – and towards other AIs.
Lucky Nations[edit]
This setting grants bonuses only to certain nations. When set to Historical, the game grants bonuses to those countries that historically came out on top during each era; thus, the game is steered to follow more closely the path of history. Set it to Random, and the countries receiving ‘Good Luck’ bonuses are selected with a weighted random die (for example, One Province Minors are unlikely to be selected). If you set it to None, then there will be no lucky nations – except for yours, of course, since yours benefits from your watchful eye.
Allow players to hot join[edit]
If set to No, then players cannot join. Your single player game will remain single player. Set it to Yes, and other players can drop into your game.
Allow players to play the same country[edit]
A popular feature from the Hearts of Iron series, where certain countries can be overwhelming for a single player to manage in a multiplayer game. If you choose yes, you too can relive all the glory and chaos of having two kings at once. Channel your inner Spartan!
Ironman mode[edit]
If you dare. When set to Yes, you don’t get to run back and reload every time a decision goes against you. You have only one save game, saved to Steam Cloud, which is overwritten at every decision point so you cannot go back on your choices. You can save, yes, but only by exiting the game (so you can go to bed). Iron manmode is the only time when Steam Achievements are active. The only way in Iron man mode to go back is to reset your computer straight after something has happened. It'll only take it back to the last event before it. Don't let it clock over the month. Don't accept any window that pops up. Just hit the reset.
