@UngainlyTitan @Fanaelialae @Xamnam Thanks for the clarification, I had indeed missed it.
It's a strange bit of advice, isn't it? I started playing D&D with the red-box Basic rules back in 1986, and there wasn't any such guidance offered. I guess I got accustomed to having the game having a certain pace to it, and that pace hasn't really changed. The rules for THAC0 and save throws and such have changed, but I still
run the game more or less the same way that I've run it for decades.
I'm starting a new campaign in a few weeks. After spending the last couple of years as a player, I'm taking my seat again in the DM's Chair (where I'm most comfortable, tbh). My previous DM had been using milestone leveling, which we later came to understand as "we will level-up whenever the DM gives us permission to" and we kinda hate it. Well, I prefer to track individual XP (see the paragraph above), and I award XP for more than just killing things. But now I'm going to be wondering if I have the right amount of combat in my game, for the first time in 30+ years.
Eh. This rule isn't going to work for me. It's trying to fix a problem that I've never had, in a way that I would never try.