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Know who inherits
before you die.

Enter your laws, your titles and your family. Get the exact split your Crusader Kings III realm will suffer on your death — heir by heir, title by title — and see what to change to stop it.

Every succession lawConfederate Partition, Partition, High Partition, Primogeniture, Ultimogeniture and House Seniority, with all five gender laws — and what each one takes to unlock.
The entire mapAll 3,476 counties, 911 duchies, 215 kingdoms and 44 empires, as the de jure map stood in 867, 1066 and 1178. Type a name; the chain fills itself.
The rules that actually biteCapital shielding, titles created for free at your death, dead heirs represented by their children, bastards, disinheritance, equal-rank co-heirs walking away.
Share the verdictOne click copies a short summary with the heirs and a link that reopens the whole realm — ready to paste into Discord or Reddit.

Four screens, two minutes

1LawsPick your gender and succession law from cards that explain each one.
2RealmChoose the start date and whether you answer to a liege.
3TitlesSearch your holdings, add whole duchies at once, mark your primary title and capital.
4FamilySons, daughters, grandchildren, siblings — alive, dead, bastard or disinherited.

How inheritance works in Crusader Kings III

When your character dies, CK3 applies your realm's succession law and gender law to every title you hold. This calculator runs the same rules so you can see the split before it happens, change your laws, capital or family, and run it again. It knows the game's complete de jure map — every county, duchy, kingdom and empire — for the 867, 1066 and 1178 start dates.

Who is eligible

The gender law comes first. Male Preference (the usual starting law) passes daughters over while any eligible son, or a dead son's line, remains; Male Only bars daughters and their descendants outright; Equal takes the oldest child regardless of sex; Female Preference and Female Only mirror the first two. On top of that, characters with the Bastard or Disinherited trait are excluded together with all their descendants, and a dead heir who left children is represented by them.

The three partition laws

Under any partition law your titles are divided among your eligible children. The oldest becomes primary heir and takes your primary title, your capital and every title the capital sits inside de jure. Remaining empires, then kingdoms, then duchies are handed out one at a time to the child who has the fewest titles of that rank or above; each title carries the held titles beneath it, and a junior heir who has received something gets nothing at any lower rank afterwards. Counties are shared out last, by county count.

  • Confederate Partition is the starting law and the only one available to tribal rulers. Before dividing, the game creates for free any title of your primary rank that you could have created — you control more than half of its de jure counties — and hands it to a junior heir. This is how a single kingdom becomes two.
  • Partition is the same division without any title creation. It needs the Hereditary Rule innovation (Early Medieval era), a feudal or clan government and Crown Authority 2.
  • High Partition lets the primary heir take at least half of the titles at every rank before the others receive anything. It needs the Heraldry innovation (High Medieval era) and Crown Authority 2; Aragonese, Basque and Catalan cultures get it early.

Single-heir laws

Primogeniture gives everything to the oldest eligible child (a dead child's line comes before younger siblings), Ultimogeniture to the youngest, and House Seniority to the oldest eligible member of your house. All three need Crown Authority 3; Primogeniture and Ultimogeniture also need the Primogeniture innovation of the Late Medieval era, while Czech and Slovien cultures can take House Seniority at any Crown Authority.

How to keep your realm together

Under partition, hold only one title of your highest rank — a king with two kingdoms will always lose one. Keep your capital's duchy in your own hands, because the primary heir keeps everything inside it as long as every other heir can still expect a duchy of their own. Extra kingdom-rank titles can be given away, and heirs can be disinherited, sent to holy orders or, for a bastard, simply not legitimized. Above all, climb the Crown Authority ladder to Partition, then High Partition, then Primogeniture.

Frequently asked

Who inherits if I have no sons?
Under Male Preference, your daughters. With no eligible descendants at all, nothing is split: the whole realm passes to your oldest eligible sibling or their heirs. With no heir anywhere, a vassal's titles go to the liege and an independent ruler's go to a vassal or courtier.
What do I need to enable Primogeniture?
Crown Authority 3 (High) and the Primogeniture innovation, which arrives in the Late Medieval era. Changing the gender law also needs High Crown Authority, or Limited Tribal Authority in a tribal realm.
Does the realm capital matter?
Yes. The primary heir always inherits the capital county and every held title it belongs to de jure — except a title equal in rank to your primary title, which stays in the division. Moving your capital changes which lands stay with your heir.
What does the co-heir get?
Their share of titles plus every held title de jure beneath them, and they become the primary heir's vassal — unless their rank equals the primary heir's, in which case they go independent, or become your liege's direct vassal if you had one. Every eligible child also gains pressed claims on the titles they did not inherit.
Which start date should I pick?
The one your game began on: de jure borders differ between 867, 1066 and 1178 (Aquitaine exists only in 867, Portugal only in 1178, Bohemia moves into the Holy Roman Empire by 1066).

1. Which laws does your realm follow?

Pick the gender law and the succession law your realm has right now. Each card says what the law does and what it takes to unlock it.

Gender law

Succession law

The realm is split among your children
One heir takes everything

2. Your realm

The start date sets which de jure map the calculator uses. Your standing decides where titles go when a co-heir is your equal — or when there is no heir at all.

Start date (de jure map)

Standing

3. What do you hold?

Search any title in the game — empire, kingdom, duchy or county — and add it. The de jure chain fills in by itself. Then mark your primary title and your capital.

Your titles

4. Your family

Add children oldest first, or give everyone an age. A dead child who left children is represented by them. Siblings and their children only matter if you leave no eligible descendant.

Children & grandchildren

Siblings, nephews & nieces

5. The inheritance

How this is calculated — algorithm, unlock requirements, limits
Eligibility
  • The gender law filters candidates: Male/Female Only bar the other sex and their descendants; Male/Female Preference defer the other sex while any eligible preferred-sex line exists; Equal ignores sex.
  • Bastard and Disinherited characters are barred with all their descendants. The dead cannot inherit, but a deceased heir's own heir takes their place in line.
Partition (all three kinds)
  1. The oldest eligible child becomes primary heir and takes the primary title plus any held title above it de jure.
  2. The primary heir also takes the capital and every held title it belongs to de jure — except a title equal in rank to the primary title, which stays in the division. Everything inside the capital duchy stays with the primary heir if every other heir still expects a duchy or better; likewise for the capital kingdom.
  3. Remaining empires, then kingdoms, then duchies go one by one to the child with the fewest titles of that rank and above (ties to the oldest). Whoever receives a title also gets every held title de jure beneath it, and a junior heir receives nothing at any lower step afterwards.
  4. Counties go to whoever holds the fewest counties.
  5. Confederate Partition first creates, for free, any title of the primary title's rank the ruler could have created (more than half its de jure counties held). High Partition instead lets the primary heir take half of each step first, rounded up.
  6. Co-heirs become vassals of the primary heir unless equal in rank, in which case they go independent (or become your liege's direct vassals). No eligible descendants: nothing splits and the realm passes to a collateral line. No heir at all: a vassal's titles go to the liege, an independent ruler's to a vassal or courtier.
Afterwards
  • The primary heir also inherits all gold, men-at-arms, artifacts and part of the ruler's Legitimacy. Eligible children get pressed claims on titles they did not inherit.
Unlock requirements
  • Confederate Partition — starting law; the only option for tribal rulers.
  • Partition — Hereditary Rule innovation (Early Medieval) · Feudal or Clan · Crown Authority 2.
  • High Partition — Heraldry innovation (High Medieval) · Feudal or Clan · Crown Authority 2. Aragonese, Basque and Catalan cultures unlock it early.
  • Primogeniture / Ultimogeniture — Primogeniture innovation (Late Medieval) · Crown Authority 3.
  • House Seniority — Crown Authority 3; Czech and Slovien cultures at any Crown Authority.
  • Gender laws — High Crown Authority (Limited Tribal Authority when tribal); Equal also needs a faith or culture that allows it.
Not simulated
  • Elective title laws (they depend on electors' votes). Heirs' pre-existing titles, Legitimacy discounts on title creation, the Hegemony tier. Within a rank, titles are handed out in the order you added them.
  • The database is the complete de jure map — 3,476 counties, 911 duchies, 215 kingdoms, 44 empires — at each of the three start dates; de jure drift after the start is not tracked.