I think your argument is flawed, especially since D&D is not a competitive game. It doesn't matter that before the change I was 15% better than Dave in Athletics and after the change I am still 15% better than Dave, because the majority use of skills is against challenges in game not against other PC's. When my effectiveness against an easy/medium/hard challenge in game fluctuates, it creates a different interaction with the play environment, and thus a difference in my character.
Guess I didn't word it right...
It's not that you're competing against Dave, that was just the easiest way for me to put it into words.
Let's say you have 3 levels of ability.
Meager
Average
Awesome
You build your character to be awesome.
The game adjusts the DCs.
You are still per the rules in the awesome category, just what that means has changed. There isn't a new category super awesome, and it hasn't moved you into the Average category, so you don't need to rework your character to get back to where you were.
Awesome may have meant succeeding 90% of the time before, and now it means succeeding 70% of the time- but there isn't a category that DOES now succeed 90% of the time. Awesome just now means 70% for everything.
If I was easily capable of scaling a wall last game and now for some reason it's gotten harder... how is this not a change in gameplay.
Sure- but that's true of everyone. There isn't a way you need to rebuild your guy to match your effectiveness. If you were great at climbing walls, you're still great at climbing walls.
In other words, if your character has been optimally built to be the best at climbing walls- he still is.
It's these types of differences that can very easily set the feel (gritty, whimsical, heroic, super-heroish) in a game. So I would argue that, yes, it is a big change.
Sure... But mostly that should be the DM's territory to decide not the games really. Whatever he wants to in the end set the DCs to.
and again- it's not that it's not a change... It's how much of a PITA is it going to be is the easiest way I can say it. If it's going to force a lot of re-working or something, or cuase certain options to no longer be valid.
For instance, if they changed skills to say now there's a climb skill, and a climb walls skill...
THAT would be a change that forces me to switch my guy around. I built him to be able to climb walls, but after the change my climb skill drops way lower then where it was built to be. I COULD optimize to be a wall climber, but through no action of mine, my climb walls skill went to being unoptimized.
Now if I want to be a wall climber I have to re-build my guy to be optimized in wall climbing.
As it stabnds now- I'm still optimized in climb- it's just gotten harder for everyone to climb walls... See what I mean?
I also don't see how going from being able to create certain magic items to it now being disallowed is not a major change in the game, as well as for some PC's in classic 4e... or the fact that you can easily end up with way more or way less treasure than before also not a change in gameplay?
The power level has not changed in MI, just new keywords, and which ones can be created.
If I have a holy avenger now, it doesn't change my power level compared to if I have a holy avenger not labeled rare.
Ok, "dramatically" might have been an exaggeration but there are differences. If I use the skill description from classic, I can identify Rituals but can't manipulate the qualities of one's magic, control outside magical phenomenon or use it instead of diplomacy (or to enhance diplomacy) with certain creatures...
While if I use essentials as my reference I can't identify rituals but can do all thew other stuff.
I don't think adding abilities to a skill description is really an issue.. After all by way of page 42 we were supposed to be doing this anyway... They've just kind of mixed it into the skills, and unlocked/standardized a few things.
I'm also guessing that when rituals show up in Heroes of Legend, the ritual bit will be added to arcana... It's just that with no rituals it would be confusing for those with just these books...
It is inconsitencies like the above that can cause two players with different sources (or even a player and a DM with two different sources) tol have skewed understandings of what exactly they are capable of with the same skill.
Sure... But specific beats general, new beats old.
In the case of the Arcana skill since it doesn't specifically say you can't do the ritual thing, it stands to reason you can.
In the case of all the skills it seems sort of to be the default the stuff you can do with the skills are just basically suggestions...
Again none of this is really a change that forces you to rebuild your character to do what you used to be able to do.
Which in the end is why I keep harping on the PiTA factor.