Do Retired Adventurers Maintain Levels?

[Thunderfoot]

This is one of those areas where realism and fantasy rules just don't mix.
If we were to look at this realistically a Fighter or Paladin that has moved from kicking butt to sitting on his butt is going to gain weight, lose reflex time and have their skills start to droop even if they "stay in practice". Their old armor won't fit, they'll get winded after a relatively short time in a fight and the old 'fightin' edge will be long gone. I think Disney/Pixar did a great job of showing this in the movie "The Incredibles"
A Rogue may be a bit rusty and the old dexterity may flag, but the skills are usually honed even in retirement. Even the best thieves and manipulators like to go out and do 'just one more' to stay in shape. And though the manual skills might flag a bit (detect traps, open locks, etc) the social skills (diplomacy, gather information, bluff, etc) should probably be as good and possibly better since that is what they are now relying on. That backstab is probably not as reliable as it used to bem, though.
Clerics may suffer the same fate as the fightin' folk due to time away from the adventuring world, (weight, dexterity, etc) but their faith based skills should be just as sharp as they ever were.
Wizards and sorcerers are probably no worse off than when they stopped adventuring, just used to that soft cushy life now, may make them a little more crotchity, but still in good form.
Druids, Barbarians, Rangers and Bards are probably still on top of their game, even if they stopped practicing as much. The way these classes work, adventuring only allows them to progress faster than their compatriots. Hunting, tending gardens, talking to animals and roaming for survival keep the forest folk in top shape while the bard is doing what he has always done, singing for lords and paupers, and staying one step ahead of the town watch/bookie/organized crime (instead of orcs, goblins and trolls). They may be leading less glamorous lives, but they are far more active than their old companions.

But the rules tell a different story. How many times has a young buck fighter tried to throw his weight around a tavern only to be thrashed by the owner? You know the one, the ex-fighter that actually took the head of that Umber Hulk that's hanging on the wall of his Inn. Or the young thief that finds out that in order to advance in the guild he has to steal an item from the guildmaster's room. Only to find out that the guildmaster not only heavily traps everything, he has false copies of items and can still hide in the shadows well enough to not be seen when he knock the poor kid out as he is rifling through his trunk.
And any high level retired spell caster almost certainly has their own church/school/retinue/grove that gives them plenty of political clout as well as actual spell casting power.

If you decide that you want to pursue the more 'realistic' path, be very careful about dumbing things down too much. Probably the best thing to do would assign a quickly depreciating penalty to whatever scores you think are appropriate and remove them gradually until they have 'worked off' the rust. And should the chracter advance in level, all 'rust' should immediately be gone. (You can't advance when you're rusty). Just my two coppers.

 

[(Psi)SeveredHead]

Also, keep in mind that with 3e rules for level-appropriate encounters, it is unlikely that a high-level NPC is going to run into anything challenging enough to result in a level boost.

And their age penalties probably make them weaker (enough to reduce CR, at least for non-spellcasters).

I don't think anything short of senility should take away class levels. Retired adventurers have a different mindset. They're not gaining levels anymore (not adventuring, few things give them XP) and they're (probably) getting weaker. They might be married and have kids, have a craft, have opened a business, suffer from arthritis or some other chronic disease, etc. They're not going to get off their butts unless their area is directly threatened* (eg bandits attacking their village, and the militia can't handle them), or "one last mission for the king". Even then, retired adventurers should probably ask for help.

(This could be a plot hook, provided you keep the higher level allied NPCs away from the lower level PCs.)

* I think high-level adventurers would also be rare, otherwise bandits couldn't keep their jobs! Lots of adventurers never reached high levels before retirement, and lots of them died (either during adventuring or simply from old age). The old group might have broken up, and they don't want to team up with anyone else (even if those someone elses happen to be equally competent but younger adventurers who look up to them).

On another note, things like a thicker waistline could be explained thorugh the aging Dex penalty. It's not within the rules, but I don't think it's a problem to change rules for NPCs, as long as it doesn't negatively and directly affect PCs. (You can just say the old mage is senile without coming up with rules for that, but don't do that to the old PC or to the BBEG!)

 

[Angel Tarragon]

Adventuring? No.

Practicing? Yes.

 

[LoneWolf23]

I doubt that a warrior-type adventurer turning into a Noble would lose his skills over time. If there's one thing that medieval-style nobles did all the time, it was fighting. They were constantly waging wars, putting down rebellions, hunting bandits and running tournaments, so I'd imagine a 15th level Fighter who'd become a Baron would find his fighting skills staying stable even at a relatively lower level of activity.