Currently, the SUCCESSION tag on positions is rather limited, and, outside of worldgen, does nothing at all. As soon as the latter gets improved upon; dealing with the former would be interesting:
Currently SUCCESSION supports BY_HEIR and BY_POSITION: (there are also ELECTED and REPLACED_BY:; which are both functionally related).
But as these methods allow for little variety in entities; I propose that a few new SUCCESSION methods be added:
• BY_LOTTERY: The successor is chosen by lottery at the death of the previous holder. (Might not play nice with nobles that aren't [SITE], as arranging a civ-wide lottery would be impractical at best.)
• BY_ASSASSINATION: The successor is whomsoever killed the previous holder. I can't think of any actual examples of civilization in real life that have used this as a basis of government, but a few fictional ones spring to mind. An interesting method for making adventurers kings and emperors, and possibly a suitable succession method for goblin law-givers?
• BY_DUEL: Similar to the above, except that leadership is only legally transferred if the previous holder is killed (or defeated, if some method for yielding in a duel is implemented) in honorable combat, or at least honorably initiated combat. This is something occasionally seen in tribal might-is-right type societies.
• BY_APPOINTMENT: Similar to BY_POSITION:; except that rather than a concrete position, the closest friend of the holder is appointed.
• BY_DIVINE_INTERVENTION: The gods themselves meddle in the affairs of mortals, and appoint a devout follower to the throne. Perhaps more relevant for priests than for kings. Of course, in the case of kings, the reason for a new king being needed in the first place might very well be equally divine intervention…
(These are, of course, just a few suggestions off the top of my head, if anyone has any further suggestions, feel free to pitch in.)
Furthermore, BY_HEIR could stand to stand to be expanded:
• [SUCCESSION:BY_HEIR:OLDEST_CHILD] (Current behavior)
• [SUCCESSION:BY_HEIR:OLDEST_DAUGHTER_OR_OLDEST_CHILD] (At the time of death, the oldest daughter becomes queen, or in the case of no daughters, the oldest child.)
• [SUCCESSION:BY_HEIR:OLDEST_DAUGHTER] (At the time of death, the oldest daughter becomes queen, or in the case of no daughters, the line crumbles, and is replaced by a new queen.)
• [SUCCESSION:BY_HEIR:OLDEST_SON(_OR_OLDEST_CHILD)] (As above, but oldest son.)
• [SUCCESSION:BY_HEIR:ANY] (Any of the above, selected at random.)
Preferably, this behavior should be possible to randomize when entities are actually created, so that different entities of the same kind could have different practices.
The most flexible syntax would be to allow [SUCCESSION:*] to take a final parameter, ratio; like so:
[SUCCESSION:BY_HEIR:ANY:5]
[SUCCESSION:BY_OLDEST_CHILD:2]
[SUCCESSION:BY_DUEL:2]
[SUCCESSION:BY_ASSASSINATION:1]
Additionally, as Nyan Thousand points out, the APPOINTED_BY token needs to be expanded to be aware of [NUMBER:]; so that if the position charged with appointing the new monarch, for instance, has multiple holders, they act as an electing council.