CK3 All Under Heaven – How to become Shogun by having lots of babies

Japan’s government is a mess in Crusader Kings 3: All Under Heaven — that’s just history and not in any way the developer’s fault. See, there is an emperor, but he actually has no power. A regent, the Kampaku, really calls the shots. So if you want to be the big man in the country, the Kampaku position is what you’re gunning for (unless you want to farm tons of Renown for your dynasty, in which case being the imperial family is quite lucrative, because every child born into the dynasty provides extra Renown).

Challenging the Kampaku right from the start is difficult, though, because the position comes with the command of a massive army that no local lord can match. You need to play the long game and use Japan’s Bloc system to your advantage.

In short, Blocs are informal alliances between noble houses with similar aspirations, of which there are several to choose from, such as Ceremony, Honor, Strength, or Prosperity. Leading such a Bloc and making it the most powerful political force in the country is the smoothest way towards usurping the regency and eventually creating the Shogunate.

The best way to grow your Bloc is not by conquest or by diplomacy, although both play their parts — no, to rule Japan in CK3: All Under Heaven it’s of critical importance to have tons of children and expand your house.

How to grow your Bloc in CK3

Growing your Bloc is pretty simple and can be done in various ways. The easiest way is to use the “Invite to Bloc” interaction on the head of another house. As usual, various factors decide if such an offer is accepted or declined.

When your Bloc is still small, it’s best to choose houses that have the same form of government and aspiration as your own: If you’ve converted your province into a Feudal fiefdom and you’re running with the Prosperity aspiration, only invite houses doing the same. This not only makes it more likely that they’re actually joining you, but also increases your Bloc Cohesion, which brings various bonuses and keeps the whole alliance from falling apart.

Inviting houses with different government types and aspirations or ones you have bad relations with lowers this Bloc Cohesion and might cause it to dissolve. Once you have amassed enough like-minded houses, it’s fine to add a couple outliers — just keep that Cohesion growth positive.

You can also strengthen your Bloc by attending Festivals, a unique Japanese Activity. Interactions at Festivals allow you to boost Bloc Cohesion, attract new members, or even sow dissent in other Blocs, setting up some shocking betrayals.

I’ve found that the best way to grow your Bloc, however, is through a mixture of growing your own family and conquering your neighbors. Being in a Bloc unlocks a Casus Belli that allows you to declare wars with the intention of expanding your Bloc. Once the war is won, you can bestow the conquered territory on a courtier or family member and the newly created ruling house will automatically join your Bloc, adopting your aspiration and government.

In this way you ensure that the Bloc Cohesion is kept, the new members are slightly weaker than you (and therefore can’t challenge you), and expand your influence over the country. If family members gain domains this way, it has the added benefit of increasing your dynasty’s overall status and creating valuable allies you can call into wars. More family branches also means more family members being born and the number of living family members in turn further increases the power rating of your house. 

It’s a political pump and dump scheme in the literal sense — pump out kids and other relatives and dump them in any piece of real estate you can get your hands on. It doesn’t matter if each brings a mere 200 or 300 soldiers to the table. Quantity, at some point, takes on a quality all of its own.

Which brings us to the endgame — why are we doing this? While Blocs are not a traditional alliance in the sense that its members will join offensive wars, they will join any faction you’re starting against your liege, such as one aiming to install you as the new Kampaku. If you’ve played your hand well and expanded your Bloc while keeping it coherent, the current regent won’t even put up any resistance and give up his position without bloodshed. And if he does struggle, your Bloc’s combined armies should be able to overcome him.

Obviously, this works best if you’ve become a Feudal Soryo and are no longer working inside the Administrative framework of appointed governorships, since this increases the odds of your family members keeping their domains. At the same time, being a Soryo is a crime against the Kampaku and gives the regent a Casus Belli against you — so keep him sweet or keep him busy while building up your strength. Once the Kampaku position is yours, the Shogunate itself is only one step away…