What is Odin Force

Why should Thor be made king when Odin is immortal?

It's because the Norse gods have to go through a little thing called Ragnarok. Basically, the true myths of the northerners are set out in the Eddas, and in them Odin and Thor are both doomed to die after killing great enemies. In the Marvel Universe, only Odin is fated to die in this battle. Thor gains control of the Odinforce and is easily driven crazy by it, which is covered in the professions: The Death of Odin, The Lord of Asgard, Gods on Earth, Spiral, The Lordship and Gods and Men.

Thor must sleep to keep control of this power, just like Odin, although he can still use his own power whenever he wants. He later uses the Force to recreate Valhalla on Earth, although the last one may have been rebuilt as I haven't kept up with the plot lately.

The reason it's present in the movies, I suspect, is that Thor doesn't really have a lot of stuff to hang a story on. His comic has always been a little less characterful than the other Marvel traits because he's not really a part of this world and doesn't really want to fit in anyway.

FoxMan2099

+1, although I found the last paragraph questionable :)

RDFozz

The trades mentioned cover the end of THOR Volume 2 (around 2003-2006 or something like that) and are one specific iteration from Ragnarok. Indeed, only the end of this run (the final act, and therefore the final trade) was really Ragnarok; Odin "died" (he has come back at least once since) before Ragnarok, which led to the aforementioned events. Marvel has shown Ragnarok several times ( THOR Volume 1, 200 (retelling of myths); 273-278 (a version of Ragnarok; Asgard is not obliterated); and elsewhere). And Odin "died" another time (especially during the Simonson run).