ToME WikiPaulMoore: I've been looking for a discussion of the effects of speed, in terms of how a "player turn" differs from a "game turn". So far, I've not really found anything (there's not much useful to search on - "speed" isn't much of a search term 
) I vaguely recall once seeing an explanation for Vanilla Angband, but I don't recall where and I'm not sure how relevant it is to ToME.
Some of the things I'd like to understand better are:
- How spell durations relate to my "actions" (action = move - is that a "player turn"?)
- How to calculate how my speed affects the number of moves I get relative to a monster.
- How fast my spell points/hit points recover (and how soon I get hungry).
There's possibly enough here for a Spoilers/Speed page, but as all I have is questions rather than answers, I thought I'd start here. I'm happy to collect the results into a spoiler page, though...
NeilStevens: I'll tell you how the speed/turn rules work. That's no spoiler.
Everything on the map, player and monster, gets a certain amount of energy every turn (these are the game turns). You normally get 10 energy a turn, but that varies with your speed. The higher your speed, the more energy you get. It's mostly linear, up until around speed 30, where it starts to taper off rapidly (+40 speed does not give +40 to energy; I don't think +40 energy is even possible). Likewise down below, -10 speed does not mean 0 energy a turn.
You get to act when you accumulate 100 energy. So at speed 0, 10 game turns equal one player turn.
Most acts will spend that entire 100 energy. Special speed effects like extra shots, the speed effects on spells from things like Mage Staves, reduce the amount of energy taken for specific acts. For example if you have an extra shot with your bow, firing it will only cost you 50 energy, so you effectively shoot twice as fast, because you're getting turns twice as fast.
PaulMoore: OK, that's clear, thanks. One further question - what units are the durations of spells measured in? Game turns? For example, my sorceror has Disruption Shield with a duration of 9+d5. If that's game turns, it's less than 1 player turn at speed 0 (OK, so hasted I'm usually at speed +46, but you get the point...)
NeilStevens: I think those things are usually measured in speed +0 player turns.
PaulMoore: Looks like it - the code seems to be in process_world() in dungeon.c, which is activated specifically every 10 game turns. (And for reference, I found the table of energy per game turn vs speed in tables.c, array extract_energy). Thanks!