I recently watched the Return of the King film with my family, and the (second-last) ending, where the "last ship" sails from the Grey Havens, prompted the thought that has led to this post.
JRRT is probably the most famous conceiver of a fantasy setting, and that setting - Middle Earth - is widely regarded as a high point for evocative, verisimilitudinous and thematically sophisticated world building.
So it's interesting to note how many "one offs", how much "ad hocery" there is in the setting:
*Gollum is a unique adversary, with his ability to live in the dark eating only fish and Goblins, his toughness, resilience, and ability to strangle, his ability to relentlessly follow the Fellowship and Frodo;
*Tom Bombadil - nuff said - but also Goldberry, and Old Man Willow on the borders of The Shire;
*The Barrow Wights, and the Barrow Downs more generally - all this adventure on the way between The Shire and Bree, yet apparently undisturbed until the Ring-Bearer goes past; and the White Tower too, with its unique Palantir;
*Gandalf's (one-time) knowledge of every spell, and the suggestion that the Mouth of Sauron is a sorcerer, yet the apparent lack of spell casting by anyone in the story but Gandalf and Saruman;
*Boromir's journey across tracts of wilderness to find his way to Rivendell just in time for the great Council, in the same world where Gimli doesn't know that Balin and all his fellow-Dwarves lie dead i Moria;
*And what I was reminded of the other day - Frodo and Bilbo, neither an Elf, both nevertheless travelling to the Undying Lands on a ship from the Havens; and despite Cirdan having sailed, Sam - by repute - later taking the same journey on the straight road; and later still, Gimli sailing with Legolas to the Undying Lands.
Although there are things in Middle Earth that are typical, even "rules" - eg the difference in the "afterlife" of Elves and Men (and Hobbits sharing, one assumes, the Gift of the One to Men); and various orders of being - the story of LotR is full of contradictions of these.
In the Burning Wheel Character Burner (Revised, p13), Luke Crane writes:
If the GM proposes a game without magic, there's always that one player who's got to play the last mage. And you know what? That's good. Before the game has even started we have a spark of conflict - we have the player getting involved in shaping the situation. Discuss the situation of the game as you discuss your character concept. Tie them both together - a dying world without magic, the last mage, the quest to restore the land. In one volley of discussion you've got an epic in the making. Start mixing in the other character concepts - they should all be so tied to the background - and you have the makings of a game. The cult priestess sworn to aid the last mage - and then spill his blood so that the world can be reborn; the Lore High Inquisitor whose duty it is to hunt the Gifted, but whose own brother is the last hope. Now we're talking.
I think
consistency in a FRPG setting, in the sense of "a place for everything, and nothing out of place* is overrated. LotR is driven by departures from such consistency at just about every point.