I was reading recently about Ultima IV, which I've never played myself,
and was struck by the similarities to NetHack in the lead-up to the
game's climax: your character in that game must acquire a bell, book,
and candle from various locations in the game world, bring them to a
particular spot, and apply the items in a specific order. Doing this
successfully triggers an earthquake and causes the ground to split open,
revealing a staircase leading down to the final dungeon of the game.
There are even similar messages triggered as each item is used (e.g.
"the bell rings on and on!" -- cf. NetHack's "the bell issues an
unsettling shrill sound...").
Here's a video of the sequence in Ultima IV:
Maybe this is common knowledge, but I had never heard of a particular
inspiration for the invocation ritual beyond the general "bell, book,
and candle" reference -- anyone know if the Ultima IV endgame helped
inspire the invocation ritual?