Once upon the time, in April, I had it figured out precisely, but as bugs were fixed, things changed.

Here's the way to think about it.

1. In order to move, an unit needs to gather a certain amount of energy.  At the beginning of the battle, everyone has 0 energy, baring traits (impulsive, for example)

2. Every tick (you can think of them as combat rounds) every unit generates energy corresponding to its initiative.

3. Every tick, the energy of units is checked, and those that have gathered enough, move.

4. Next tick. I.e. go to 2.

Once again, this is not necessarily how the game works.  This is a model that worked in April.

A few things that you can conclude from my model:

1. An unit with half the initiative moves about half as often.

2. Because energy gathering 'overshoots', the order can change in unexpected ways.

3. When initiatives are close, it takes a long time for a faster unit to get one whole turn on another, slower one.

4. If initiatives and ticks fall just right, a slightly slower unit can move twice while a faster unit gets no turn.

isn't there some way to make a definite "end" to a turn so that cumulative bonuses and penalties don't spiral out of control? I know they seem to have hard coded a minum 3% initiative, but is that enough of a roadstop?

I like haveing regeneration in combat, but the current initiave model makes it broken.

How can you change it so that you have distinctive rounds occure, you have your multiple turns in a round, regeneration fires once, and then a new round starts,

rather than regeneration firing evey time your high initiave unit has a turn.

Because regeneration would tick every time the regenerating unit would act, rather than having its own "turn" to regenerate everyone with the ability.  This meant that a high-init, high-move unit was essentially immortal against a single opponent, and could recover from any non-fatal injuries taken before the end of a battle, good as new. 

Anyway, Sean and Tuidjy already answered your question pretty well, but I'll add this: barring other modifiers, 1 init is 1 extra action against a unit with 1 init.  IE, 2 init gives you 2 attacks vs 1 init, while 20 gives you 20, and so on. 

i'm sorry, i know it doesn't activate in combat any more. I was asking about how to put it back into combat, but limit the the regenration firing once in one round of combat, with a unit getting x number of tunrs in a round based off of initiative. I want the retroactive effects to stop.

I want to calculate number of turns a unit gets based off of initieve. every body takes those turns. end of round 1, regen fires.

check for any change in unit initiative, everybody takes turns based off of initiative. end of round 2, regen fires.

instead of regen firing every time a unit gets a turn, that's the broken part.

err, wouldn't that have you regen less than 1 hit point ? or would it regen, say by example .5 a hp, so the 2nd time it kicks in your hp go up by 1 point.

uhg that will need testing, but otherwise, it's a very good idea to fiddle with.

Regeneration in combat was really unfun because my fast hero with a horse would run around for 5 minutes regenerating to full then hit the enemy once, then repeat, and defeat much stronger yet slower foes in 20 minute or more battles.

I think the change makes the game more fun. You can still use this technique by waiting until your hero gets a double turn and spend one turn going in and attacking and one turn running away again. This is very unfun and could be fixed with zone of control. Where if you are adjacent to a foe and move you either get only one step or you take a free swing like Age of Wonders did.

Mike.

I really miss this. Although I don't usually do the hit and run, I sometimes move champs/troop through enemies to finish a wounded one.

A hit (that could be dodged) by each enemy that is in range (1 tile) when trying to move out  (that happened in AoW but in MoM too I think) is a solution for the hit and run.

My guess is that you had Impulsive, which gives you a huge boost so you start first, but often other units get two (or maybe more) before you get your next move because your initiative has dropped off since your first move.