Or I may just PM Fliggerty, since he seems like he'd be the go-to man for this.
Blasphemy :hehe:. (though to be serious, I'm sure he knows more about MWSE and similar than I do)
Technical stuff:
The script fragment Fliggerty posted earlier should certainly work as far as it goes. The problems start to arise when you add in all the fortifications/curses/damages/drains/abilities... to screw with things - not to mention scripted changes by other mods. GCD handles this by keeping track of a character's natural skill values from the beginning of the game, then using a scripting trick using player->mod
skillname to detect whether increases are natural increases or magical. Once you know the natural skill value, you can then use some other tricks to limit the natural value to, say, 40 or 70, while preserving any magical fortification.
This stuff is explained in Morrowind Scripting For Dummies 9 from pages 113 to 116. It's not entirely perfect, but it works most of the time - and the vanilla system isn't without its bugs either. Once you know the base value of a skill, restricting it to 40 or 70 using mod
skillname and set
skillname as described there shouldn't be too hard.
An alternative method would be to do what Madd leveler does, and assume that any skill increase of 1 is a natural increase, and that other increases can be ignored. In theory this could go wrong a lot, but in practice spell-effects and mods very rarely (never?) increase skills by only one point, so it works pretty well. So you could just check whether the skill is over 40 or 70, and then modskill down by one every time you detect an increase of a single point. This wouldn't be perfect, since characters who'd reached 70 through a magical fortification would be kept to 70. If they were wearing a fortifying item, they could remove it, gain some skill, then reapply it - but that doesn't work if it's a curse/ability.
Of course MWSE might be able to handle things properly - I'm not sure. One aspect to watch out for there is that a function to detect the base value of a skill might not include any ability bonus; that differs from the modstat-based detection method above, which doesn't distinguish any ability bonus from the base stat value. This might make things easier/harder, but it's something to be aware of (it might not be true anyway - but I think it was a few years back for the attribute detection functions).
That's about it on that front - I can't really say more than is already in MSFD and/or the explanations in GCD scripts (Gals_Sk_Acrobatics might be worth a look). These were written back when I knew what I was talking about, and hadn't forgotten a load of stuff.
Compatibility between BTBGI and GCD:
There's little that strikes me as obviously problematic (I haven't looked at BTBGI in any detail). The changes to level increase GMSTs (the ilevel... and similar) could cause trouble if they've all been adjusted - i.e. both the value required for a level increase, and the amount gained for a skill increase. If both have been changed, you'd get conventional level increases alongside GCD level increases, which isn't good. Fixing this should be pretty simple for anyone who can open the construction set - just don't use BTB's changes to these GMSTs. If the total required for a level increase hasn't been altered from 10, there shouldn't be any trouble - GCD sets this to 32000 for this reason.
I've seen something about a birthsign script in places, which seems to have people worried about compatibility. I'd
guess it's not an issue, but I can't say for sure without knowing what that script(s) does - what does it do? GCD ought to work with most alterations to birthsigns. Scripted stuff could potentially conflict though.
GCD is written to adapt to different starting attribute values, so there shouldn't be an issue there. Mmost calculations are done by comparing a starting attribute value to the average of all the starting attribute values. So if BTBGI reduces all starting attribute values, while maintaining some variety, there shoudn't be any real problem.
Changing the governing attributes of acrobatics and hand-to-hand shouldn't cause any trouble - GCD will basically just ignore it. Physical skills already have an impact on all physical attributes with GCD, so the standard governing attributes are already 'wrong' in some sense.
Some thoughts on the hard-skill-limits vs soft-limits vs no-limits debate:
Mostly I agree with BTB's take on things. I can see an argument for hard limits, but I still prefer soft ones on balance - at least in a GCD-like context.
One important point to note on the soft limits in GCD is that while it's always possible to increase any skill, it's much faster to increase major skills than misc skills. This means that achieving god-like misc skills isn't simply a question of player patience - it's a question of priority. Certainly a player
could always increase his misc skills further, but if the choice is between spending a few hours to increase a major skill by 5 points, or a misc skill by 1 point, most sane players are going to go for the 5 points - at least until their major skills become extremely high. On top of that, increases in skills translate into attribute increases, and a character's best attributes increase much more readily. This means that even once increasing the major skill is just as hard as the misc (at a much higher value), each point gained in a major skill will result in a greater increase in attributes. Major skill increases also have a significantly larger impact on PC health. So while it's possible for a player to increase all misc skills to high level, it'd largely be a waste of his time - in all but a few cases, he'd do much better by increasing major skills further. [counter-intuitive increases of endurance-related skills being an unfortunate exception, admittedly]
The numbers I used for the default version of GCD aren't as harsh as I would personally advocate: I wanted to provide a default version that would give the majority of people something they were happy with. I'd personally prefer settings that had significant skill slowdown kick in sooner - e.g. after 40 rather than 60. I'd also personally prefer a somewhat harsher rate of slowdown - so in practice, getting a misc skill beyond 60 would be near impossible. There's info on doing this in the GCD readme, so anyone who wants things to be harsh can have them that way.
One of my main objections to hard caps isn't the fact that they're harsh, but rather that they serve to remove variety (compared to soft-but-harsh caps). In the same way that the 100 limit makes all characters eventually the same, hard caps at 40 and 70 will leave all characters with a given major/minor/misc skill setup the same. Certainly it's an improvement over 100-in-everything, but I think it's far from ideal. I think it's right that a character's initial setup should have a great impact, including some harsh restrictions, but I'd want the way he acts in the game world to have an impact too - even in the very long term.
That said, I'd point out that GCD isn't my ideal solution - it's just the best I could do. Ideally I'd have included skill atrophy too - but based on skill increases, rather than on time. I'm not keen on time-based atrophy, since Morrowind isn't a time-based game in almost any other sense. In a game with time pressure throughout (a good thing), I think time-based skill atrophy would be appropriate, but for Morrowind, I don't think it's the best way. I think I'd like a system that removed say 1/50 of a point from every skill, each time any skill was increased by a point (or an average of around 1/50 - perhaps less for related skills to the one increased). This way you'd be losing 27/50 of every skill increase, and your skills would change to fit your approach, and remain varied without becoming godlike. Of course you could increase the proportion of atrophy as the character's total skill count increased, so at some point you might be losing as much as say 48/50 of each point - so your actions would no longer be making you significantly more powerful, but rather focusing your skill into the areas you were actively using.
I didn't do the atrophy thing, since by the time I thought of it, it wouldn't work with the rest of GCD without significant reworking. It's a thought as an alternative to a hard cap though. E.g. you could use something similar to the above, but have atrophy be significantly 'faster' for misc skills than for minors/majors. You could have each increase by one point to a skill result in a tiny decrease to major skills (e.g. 1/100), a small decrease for minors (e.g. 1/40 to 1/60) and a significant decrease for miscs (e.g. 1/25 to 1/40). That way you'd ensure that no-one could raise a significant number of misc skills high without an absurd amount of effort, but you'd keep some dynamism and variety, rather than having the character sheet end up looking like 40, 100, 40, 40, 70, 40, 100, 70, 40, 40, 40..., which is a little lacking in charm.
Just a thought anyway.