Maybe I misunderstand the change?
If an archer started at 0 XP and attacks every turn in standard, it would reach its 4th promotion at a certain year, right?
Now if an archer started at 0 XP and attacked every turn in epic, it would reach its promotion at about the same year (due to the change), correct? So after the change, the two difficulties will play more similarily than before.
But if you add in a barracks or armory, now the standard archer is leveling up faster than the epic archer. Furthermore, 10 flat experience is now worth less in epic than in standard. Wouldn't this mean that certain unique traits, such as orders, Assyrian great works, or Swedish-general births and now worth more on standard than on epic?
What I think Gazebo is saying is that Epic and Marathon also have a higher percentage of turns at war. Now, he would know waaaaaaaaaaaaaaaay more than me how AI vs AI combat works, but that's not the case for my wars. I think Marathon is theoretically most fun, but I stopped playing it because wars are so short and easy. If they were of equal duration, I'd still be playing it. I research Chivalry and Physics, do some quick upgrading or buying, my neighbor almost certainly doesn't have Castles researched and built. Probably doesn't have Pikemen. So I descend like a pack of vultures and the war is over before it even started. Rinse Repeat. I've had exceptions, some really long Marathon wars, but they are definitely exceptions. Whereas on Standard, the AI has more defenses built and can replace them faster.
I, in fact, would guarantee that if I played a Standard size 8/16 Pangaea on Standard speed and a Standard size 8/16 Pangaea on Marathon (or enough games to be statistically significant), by the time I won the game my highest level units would be more leveled on the the Standard speed. And I mean before this change even, when promotions cost the same. It would be way later, so 'promos per tech' would favor Marathon of course. But I find that 'percentage of turns at war' goes down as game speed slows. I mentioned exceptions above for Marathon, my standard speed 'exception' was a game as Portugal I fought The Ottomans from the late Ren all the way the til I built the Spaceship. And there were no Christmas Day soccer games going on, no armistices. That's probably not possible with war weariness now. I'm just mentioning it, because while the slowest wars on Marathon can be slow, the slowest wars on Standard can be reeeeeeeeeeeeeally slow as well.
But like I said, Gazebo would know way better how AI wars work.
XP from combat was not changed, only the threshold needed to level up. I absolutely and unabashedly agree that XP from buildings etc. is weaker. But I also note that the duration and frequency of conflict (and the fact that XP gained in battle is the same on both speeds) means that, for the duration of a game, epic/marathon units are going to gain XP such that the lower starting bumps from buildings etc. will be offset.
Edit: Perhaps I'm misunderstanding, however what I'm trying to avoid is some sort of weird XP scaling system through which XP from combat etc. scales. I want to avoid that because the numbers are so small.
TL;DR - longer games are made much easier for humans because promotions are easy to come by. Longer games now required more in-combat XP to achieve standard speed results.
Edit edit: To note, I'm not necessarily against changing it (even if I disagree on it), but I do feel that my rationale makes sense as a curative to the relative ease players seem to have on longer speed games.
G
Well, no, I don't think anyone is suggesting the XP gain from combat scales, only from the buildings, wonders, etc. If both of them technically being instant yields means they can't (easily) be decoupled in the code, then say so, and, yeah we'll have to deal with war buildings being worse on the speeds where war is still easiest. That's not the end of the world. This is such a good change overall that its more than worth it. But if they can be separated and scale, I agree with the others that they should. For one thing, it hurts the AI if they don't. The higher percentage of XP that comes from active XP (fighting) and the less from passive XP (buildings) the better that is for player. My units are still the ones more likely to survive the war after all. It doesn't negate the goodness of the change, but it does start in that direction.