Succession/inheritance is not necessarily as straightforward as might be assumed. The archetype would be primogeniture (sometimes male), whereby the oldest child (perhaps eldest son) gets the lot, and the younger children end up with either nothing or very little.
This was certainly the case in England and Scotland. However, in Wales things were done differently. There, every son got a share of the land/wealth when his father died. Sounds more equal, but it also led to fragmentation of wealth and power, whereas in England/Scotland the estate was kept whole. This meant that political power in Wales was weaker because there was a larger number of weaker nobles, whereas elsewhere in Great Britain there was a smaller number of more powerful nobles. This is one reason why England kept thrashing Wales in wars.
Another unforeseen consequence of the Welsh system was that if you killed any of your siblings, you’d get more inheritance (or claim their territory if your father had already died). To an extent this was true elsewhere, but you’d need to be next in line to benefit.
A similar system was used by Charlemagne. Splendid leader of men, but his system of his inheritance was rubbish. It led to (his grandchildren, I think) splitting his empire (roughly France and Germany) into three parts. You can guess what happened next. Infighting, weakness, etc. The French bit shrank for centuries until gradually reasserting itself (which was aided by a combination of Henry II’s stupid compromise over Aquitaine and King John’s general treachery).
But there are other systems of inheritance available. The Montenegrins, before being shamefully shafted by the Allies after World War One when Serbia took over, had an interesting one whereby the nephew of the ruler took over. That’s odd, but does have certain advantages. The typical coup comes from a brother of the ruler or the uncle. But this system reduces that chance significantly, because the brother is likely the father of the heir, and the uncle may well be the ruler already. (As an aside, Montenegro was ruled by a prince-bishop, itself an interesting position).
Typically in history, the eldest inherited. But there is a drastic alternative: ultimogeniture. This involves the youngest getting the estate, the reasoning being that older children have had more opportunity to forge their own fortune. In old Mongol times, so I’ve heard, the youngest child would inherit the ancestral lands, and older children would only keep territory they had conquered.
The Rota system isn’t taking turns on a regular basis, but sees the crown pass from brother to brother (then to the eldest son of the eldest brother who ruled).
The election of Queen Amidala in The Phantom Menace might seem rather contradictory (after all, monarchy and elections tend to be different things). But there are real-world examples of both co-existing. One of the most famous examples would be the Saxon Witan, a group of senior figures in a kingdom who would choose as successor to a fallen king whomever they felt was best. This worked quite well when they picked Alfred to be King of Wessex.