Let's crunch some numbers
Of course, we're also ignoring racial bonuses, magic item bonuses, feat bonuses, etc.
Well, then lets crunch some numbers.
I got two 4e PCs Sadie, a human wizard, and Adrian, a elven rogue. (I’m tired of halfling and half-elf rogues) I got them both at 1st level and 24th level, just for comparison.
Skills compared: Acrobatics for Adrian and History for Sadie (I didn’t choose arcana for reasons I like to think are obvious.)
Twinks used: I used the background rules from PHB to get a +2 to the corresponding skills. Both characters have skill focus in the relevant skill. Both characters also have racial bonuses in appropriate score, and both skills are keyed off their highest ability score. Needless to say, the numbers are mirror images of each other.
Foolish assumption: I’m assuming this is a game where history matters.
First level
DCs Easy: 5 Moderate: 10 Hard: 15
Adrian: Acrobatics: +15, History -1
Acrobatics Easy: Auto Success, Moderate: Auto Success, Hard: Auto Success
History Easy: 6 or higher, Moderate: 11 or higher, Hard: 16 or higher
Notes: What surprised me in making this character was that intelligence is a good dump stat for rogues. The Int skills, Arcana, History, and Religion aren’t important to many rogue character concepts and dexterity can be used in AC and Ref calculations. Particularly when one remembers that wisdom and charisma are more useful to most rogue concepts.
Sadie: Acrobatics: -1, History +15
History Easy: Auto Success, Moderate: Auto Success, Hard: Auto Success
Acrobatics Easy: 6 or higher, Moderate: 11 or higher, Hard: 16 or higher
Notes: Again, the use of dexterity as a dump stat doesn’t seem to bad when one considers that intelligence can be use instead of dexterity for AC and Reflex defenses. This was probably more illuminating to me than anything about skills.
24th level
DCs Easy: 16 Moderate: 24 Hard: 29
Epic level Adrian: Acrobatics: +30, History +12
Acrobatics Easy: Auto Success, Moderate: Auto Success, Hard: Auto Success
History Easy: 4 or higher, Moderate: 12 or higher, Hard: 17 or higher
Notes: Easy got easier, but moderate and hard got harder by one. This was surprising. Some people may think that a 4 for easy is bad, but my thinking is that the DC is easy for a reason. Under the old DC from the unerretaed DMG, our rogue wouldn’t know much history, even easy history because the DC would be 28 and Adrian wouldn’t get that except on a 16. That doesn’t seem very easy to me. Of course, I gave Adrian Agile Athlete so the chances that he’ll get a higher number are increased.
Epic level Sadie: Acrobatics: +12, History +30
Acrobatics Easy: Auto Success, Moderate: Auto Success, Hard: Auto Success
History Easy: 4 or higher, Moderate: 12 or higher, Hard: 17 or higher
Notes: Same as above, with an addition. Acrobatics is one of the skills a PC can use to end a grab. (The other being Athletics, which Sadie has a +13 in.) If a Fell Wyvern grabs Sadie (not a bad idea, really) Sadie can try to escape by rolling Acrobatics vs. Reflex, but she won’t succeed. (Same is true if she try’s Athletics.) So, even with the add half your level, Sadie’s SOL if she’s grabbed by a Fell Wyvern. (And the Ref 34 isn’t that bad for the Fell Wyvern’s level.) Adrian succeeds on a 4.
For what it’s worth, 1st level Sadie can break free of a grab on a 13 with acrobatics or a 9 with athletics if the grabber is a 1st level Kobold Skirmisher.
And lastly, if the PCs have to balance on a narrow and unstable surface (DC 25, based on page 181 of the PHB), Adrian succeeds automatically, but Sadie needs to roll 13.
What about a non-twinked out skill like perception? At 24th level Adrian has a +23 while Sadie has a +13. If a Voldsoul Specter is in the area and rolls a 10 on his stealth check he gets a 35, Adrian only needs an 11 to find him. Sadie, however is screwed again, she will need Adrian to detect the monster.
On one hand, these are extreme situations. On the other hand, their not that unrealistic given the different archetypes at play. Adrian is a skilled rogue with a good skill set just like I would expect based on the rogue stereotype I’m familiar with. Sadie’s good an arcana and esoteric knowledge, but isn’t very observant or a quick thinker. She could almost fit the absent minded wizard stereotype.
I’ve included their character sheets, just so you can check the math.