Your Monarchs Heir

[Great Mexico]

Heir the Imperial Crown of the Mexican Empire Frederick Hapsburg

[Maraque]

None.

The people will choose the next monarch, much in the same way they have for the last 4203 years.

[Auzkhia]

Crown Prince Ludwig Ferdinand Zvonimir Von Habsburg-Lothringen

Now, the heir apparent is Crown Prince Franz-Otto.

[Freustria]

The Heir to the Kingdom of Freustria is Henri's IV younger brother Charles

Prince Charles

[Modern Gondor]

Our recently appointed Grand Leader, Lord Sion the Painless, heir to the throne after the "disappearance" of his father Lord Sauron:

[Saurisisia]

MT/FT

Without a doubt, Prince Alcoris II will succeed his father, Ragnon V, as King should anything happen to his father.

PMT

With the throne of Drakonia, that's a little complicated. Considering that King Alcoris' currently only child Tigris is still merely a hatchling, there is little way he can currently inherit the throne. Should anything happen to him, his wife Queen Warenya will become Dowager Queen and rule in her son's stead until he is old enough to be crowned King. In the event of her absence, Prince Sadras, Alcoris' fiery-tempered younger brother, shall be crowned King. Alternatively, the King's niece and nephew, Prince Flamûs and Princess Faedra, will rule as Co-Regents instead. Should any of them be incapacitated or otherwise, then the Court will select the closest-living relative (Alcoris' uncle Paladin Ignit, as a Paladin, will be considered ineligible unless there is no other choice available).

In King Julius Tyrannus II's case, that's going to be a problem. He currently has no offspring or bride to succeed him upon his death. The closest living relatives he has are his uncle, Patrick Octavius, his cousins Marcus Lutetius, Thomas Rex, and Claudia Aurelia, as well as his niece Angela Nanos.

[Khiosa]

The King's current heir, Crown Princess Helena Matamos

[Eahland]

I don't currently have an ierfenuma. Should I leave the throne for whatever reason, the witenagemot would vote to select the next cyning. It's theoretically possible that they could select any æþelboren adult, but, as things currently stand, as a practical matter, it would almost certainly be my brother Þeodric. In six years, though, the eldest of my sister's children will reach his majority, followed three years later by his sister, and two years after that by their youngest sister and my brother's eldest, and then the selection would be more interesting...

[Garlas Agea]

This is Baenlin Abamora, the current Talahir's son.

[Great Manchukuo]

Crown Princess Zhong Chen Xu is the Empress's recognized heir-apparent.

[Lacus Magni]

The Corona Princeps is Lucius Claudius Masaloi Commodus, the Prince of Lusitania. He is 2 years old.

[New Vinland]

Being a Commonwealth Realm, the heir to the throne of New Vinland is Prince Charles - the same Prince Charles who is also heir to the thrones of the UK, Canada, Australia, New Zealand, etc..

[Cerillium]

We haven't one (yet).

[Insel des Mondes]

Her daughter, Grand Duchess Malala Eva Ingle. The crown is hereditary, passed down from Mother to Daughter.

[Estainia]

Retconned.

[Rafigan]

After Emperor Markus dies, the next Emperor shall be his eldest son, Grand Imperial General Venosfos.
If the General is also dead, then the younger son, Chancellor Lydon shall rule instead. If both sons are dead, then the thrown goes to the Imperial Regent Freadeline. If there is no Imperial Regent, then the people will elect a High King to become Emperor.

[Astralsideria]

On the occasion of the death of His Imperial Majesty The Emperor Jean-Victoire IV, he will be succeeded by Her Imperial Highness The Princess Isabelle-Marie, Princess of Arcabosce.

[Bayulem]

The heir to High King Shuleyos as High King will be whichever of the Lower Kings is randomly drawn to succeed him in 3 years. His heir to the Low Kingship will be his daughter Princess Nemurya:

[Archlemeinge]

Clarch Archlemeigne is the founder. He may choose a family to be the next monarch when the country is organized.

[New Zepuha]

The Heir to the throne of New Zepuha, Karl von Auschlogen IV. AT 23 years of age and his father Karl von Auschlogen III being at 68 we should be up for a new rotation pretty soon.

[Cill Airne]

Archduke Alexandre Louis-Phillipe, the emperor's younger brother, is considered heir apparent. Once the emperor is married and has a child, that child will replace Alexandre.

[Potlimitomaha]

Prince Equaliti.
((computer trouble, copy and paste the link to google images) man‑in‑kilt‑233x300.jpg 233 × 300 - To celebrate his Scottish heritage, the 19 year).

[Inutoland]

We don't know. High Tuyas Tanese Aroca's death will trigger an election to the Tuyasate of the state of Nala, her home state.

Of course, if her 12-year term as High Tuyas expires before her death, as it is likely to, Utahe Silica (or her successor as Tuyas of Moro should she meet her demise before 2022) will succeed her as High Tuyas, being next in rotation.

Confederation of 9 elected-monarchy states with a conciliar overall government does funny things to the succession.

[Kingdom of Phoenixia]

Thanks to a dynasty that ruled the country since nearly 1000 years the successor procedure is relatively easy.
Current heir is Crown Prince Frederik Eirikson (21)

[Stern des Meeres]

There isn't one, yet. The Queen is only 16, and she is expected to have an heir by the time she is 19.