A guide to Personal Unions I made to help myself

General Guide to Personal Unions

• Look for disputed successions and royal marry. You might get a succession war, a free union, or your dynasty on their throne.

• Royal marry same-dyntasy nations. If they have no heir or a weak claim heir, claim throne and take PU.

• Have higher development than other potential successors. If a country would have a succession crisis, it takes the nation with the best claim (claim>dynasty>royal marriage), and if there are multiple eligible nations in the bracket it takes the nation with the highest amount of total development (after autonomy). If your rival gets a succession crisis, sometimes you will be pulled in as an attacker against their claim (It used to be thought that prestige affects this, but it was disproven).

• You need a higher prestige than the target to claim the throne of a nation, so keep your prestige high. As well, you need to have a higher prestige than a country to have a noble from your house succeed to their throne (without event).

• Curry favours in countries you want to have your dynasty. In 1.32 you can appoint an heir of your dynasty for 90 favours if they have no heir. Getting the same dynasty means an easy PU later.

• If you have 4 royal marriages, you can get Marriage Policies Pay Off. MTTH reduced with 6 marriages. If you have a royal marriage and they don't have an heir, they get an heir of your dynasty.

• If you have high diplomatic reputation and Poland is elective, you can support heir and eventually get your dynasty on their throne. From there you can get an easy claim on their throne and one/two easy PUs.

• Diplomatic reputation is useful for inheriting and integrating, keeping good relations, and increasing the chance of accepting diplomatic proposals (including the acceptance for a royal marriage). Note, inheriting an elector transfers their electorship to you, but it won't by integrating.

• You should also use the nobility estate privilege to avoid the dip rep penalty, and for the diplo annexation cost. Combine Economic and Influence ideas for an additional 45% reduction, meaning all integrations are 1/2 off. Remember diplomatic annexation requires 20% less than conquering and coring, too, and you don't have to spend even more to make it a full core. If you are Catholic, you can also use the Send Papal Legate for an additional 10% reduction.

• Bohemia, Milan, Burgundy, and Poland are all decently easy targets for any nation to try PU near game start.

• You can continuously disinherit your heirs until you get the dynasty from a royal married nation. To do this, it's preferred to instead have your only royal marriage be with that nation, and you also need them to have at least 4 royal marriages (yours included). This can be counter-intuitive to your normal gameplay though, so I'd only do this to weed out specific high-value targets, like Spain or Russia. Also I would most of the time start with diplo ideas, it makes truce breaking which is very important in obtaining PUs hurt a little bit less.

• It helps with breaking royal marriages if you are the Curia Controller or you have Diplomatic Ideas finished. Either will get rid of the stability hit and let your marry and break as much as you want, including removing the marriage before you declare your claim.

• With the notes above, I would recommend taking Diplomatic, Quantity, Administrative, and Influence as your starting ideas. Quantity will help with early wars, and combines with Diplomatic for Dip Rep +1. Switch up the orders as your game requires, but it's typically good to have admin ideas in your 3rd or later slots, so you aren't using your points that unlock idea groups on ideas early on.

Specific nations' PUs

(F) means formable. You can usually take the missions from forming them to get their missions to PU, and if you are early enough you might get some PU events too.

Start means you start with the PU

Event means there is an event that can fire to give you a free PU over the nation

Mission means you get it through your mission tree

Claim means you either share a dynasty from game start, or can easily secure your dynasty on their throne

France (F)

• Burgundy (Event)

• Milan (Event)

• Naples (Event if you kill Provence before Naples breaks free)

• Bohemia (Claim from early marriage getting your throne, before they choose the other leader)

• Provence/Lorraine (Claim)

Austria (F)

• Hungary (Claim/Event/Mission)

• Bohemia (Claim/Mission)

• Bavaria (Mission)

• Poland/Lithuania (Mission)

• Burgundy (Event)

• Milan (Event)

• Castille (Event)

Castille (F) (End Game Tag)

• Aragon (Event)

• Naples (2 Events)

• Portugal (Mission)

• Navarra (Comes with Aragon most of the time through their PU event)

• Great Britain (Mission)

• Austria/Bohemia/Hungary (Mission)

• Burgundy (Event)

Poland (F)

• Lithuania (Event)

• Bohemia (Mission)

• Hungary (Mission)

England (F)

• France (Mission)

Lithuania

• Poland (Mission)

• Muscovy (Mission)

Bavaria (F)

• Ingolstadt/Landshut/Munich (Event)

• Denmark/Norway/Sweden (Claim)

• Palatinate (Mission)

• Brandenburg (Mission)

• Austria (Mission)

Bohemia

• Brandenburg (Mission Event)

• Saxony (Mission Event)

• Hungary (Mission)

• Poland/Lithuania (Mission)

Denmark

• Sweden/Norway (Start)

Brandenburg

• Augsburg/Bayreuth (Event)

Aragon

• Naples (Start)

• Navarra (Event)

• Castille (Event)

• Portugal (Mission)

Provence

• Lorraine (Start)

• France (Claim)

• Naples (Mission)

• Aragon (Mission)

• Hungary (Mission)

Burgundy

• Holland/Brabant/Flanders (Start, but integrated if falls under PU though Burgundian Inheritance chain)

Hungary

• Croatia (Start, but insta-integrated)

• Naples (Mission)

• Poland (Mission)

• Bohemia (Mission)

• Austria (Mission)

Palatinate

• Bavaria (Missions)

• Bohemia (Mission)

Netherlands (F)

• Britain (Event/Mission)

Please leave any corrections or missed info in the comments, and I'll add it to the guide.