Delta said:
(sigh) Okay, "first level or less", then. Here are quotes:
- 1E DMG p. 191: "City guard:... 2-16 mercenary soldiers... 1 higher level leader... in addition to the 0 level guardsmen."
- 3E DMG p. 150: "In a community... 1st-level individuals... 5% are warriors.... like this... One 3rd-level warrior (constable), Nine 1st level warriors (two guards and seven militia members)."
Etc.
Provide quotes if you're finding something different.
No, you're absolutely right if the PCs never enter a community of more than 200 individuals, which is certainly possible, but not always plausible, especially if the campaign features buying and selling of magic items or getting NPCs to cast high level spells on their behalf.
In a large community, you're going to have a significant number of fighters (tied with the number and level of rogues, on average), which are just slightly behind the number of warriors above level 1. (DMG 3.5 138-139).
Now, it's certainly possible that they're all ex-adventurer bartenders, but probably not. A certain percentage of them, depending on what sort of community they're in, are likely to be the elite guards that would be sent to, say, take on a rampaging group of level 15 NPCs.
It only takes a small city and a lucky roll by the DM for the top level fighter in town to be level 14, and to have a pair of level 7 captains, a quartet of level 4 lieutenants, and so on. And, in that small city, there will also be barbarians, bards, clerics, paladins, rangers, sorcerers and wizards. Whoops, sorry, double that; I missed the "roll twice" notation there.
Unless this is a city run by the truly stupid, a fair number of those individuals will either be on the payroll or have a standing agreement to troubleshoot when the rampaging band of Chaotic Stupid PCs roll into town.
So, yes, the group of (let's say) six level 15 NPCs won't be surrounded by level 15 guards. They will, however, have multiple level 14 NPCs, twice as many level level 7 NPCs and four times as many level 4 NPCs showing up if they step out of hand.
That's a far cry from "Ha ha ha! I am Invincible Amoral Man! Hand over your wenches and no one gets hurt!"
And that's just the RAW. I'd assume in games that aren't meant to devolve into Monty Hall lunacy, there will be other repercussions if PCs go on a rampage, as previously stated.