Aside from hopes for a spiked mace echoed throughout eternity, given any thought to taking a hammer and chisel to the FATE point system from Arcanum to roughly adapt for Infra Arcana as a balance/flavour-aiding tool? For whatever reason, it really just jumps out as thematically a better fit for IA than just about anything else that comes to mind in the Roguelike world.
Oh wow, this is crazy, I was just thinking about something like this today!
I don't remember what the fate points does in Arcanum though, haven't played that for many years. But what I was thinking about was something like "Fate cards" you could play to alter the world, or change events. It would be inspired by tarot cards, like you could play "The Sun" to remove all darkness from the level, restore your shock, and cure all negative mental effects. Or you play "The Moon" to visit a dream world. Or "The Hermit" to remove all monsters from the level.
It's hard to think of good effects though - it must not be just another consumable like potions and scrolls - it must really feel different. Sure, you could have a card like "Strength" that restored your HP. But that would just be a health potion with a different name. Not very impressive.
If this was a board game, an obvious use would be to play these cards to re-roll failed dice rolls. But in a game like this the interface doesn't allow it - you can't ask after every failed attack or failed dodge "Would you like to play a Fate card and re-roll this attack? (y/n)".
What did you have in mind with the Arcanum fate points?
Edit: After some brief reading, it seems like the effect of Fate points in Arcanum is to guarantee that your next action is successful with the best possible effect. I guess that could be worked into the game, you use a point (which does not spend a turn) and then perform some action with the best possible effect. Sometimes there could also be "upgraded" effects that you'd never see otherwise. For example if you drink a potion of insight on the turn that you use a fate point, all your items are identified, not just one random item. Or if you shoot at monsters standing on a line, the bullet continues and kills the next monster too (although this can already happen with the shotgun if they are adjacent). Also bad stuff could happen for your enemies during this turn, like their guns explode when they attempt to fire them, or they fumble and drop their weapons, etc.
Edit 2: The second system sounds more interesting (or at least easier to make more interesting). It sounds fun as a player to discover and learn what kind of effects can happen when a fate point is active.
