D&D General "For 4 to 6 characters of 6th to 9th level" - Notes on the intro to a Dungeon adventure

[Lyxen]

The point is, that multiclass characters would likely be various levels simply because of the way the xp table worked. The exact numbers really aren't this issue. And, yes, calculating the value of a multiclass character gets really, really wonky.

We used to do +2 to the lowest class if he had two classes, and +3 if he had three, but honestly it depended so much about the magic items than the level that, in the end, it was as often the reputation of the character as being deadly or not, or having other friends that he had adventured with in the party that let us know whether he was in the right range or not...

 

[Doug McCrae]

There was also a much different approach to the game in the earlier days.

At leas in my experience, players had binders of characters that they have played over the years. When they sit down for a module, they go through their characters and figure out what to play. I may pull out my 5th level dwarf, Dorbo for one game, whereas another night, it may be my 2nd level magic-user.

People don't still do that?

I started in 1982 and I've only once encountered the player with a binder of characters -- in the very early 90s, at university. "Stan's folder" became infamous in our circle as Stan would always pull out something more powerful -- higher attributes, more magic items -- than the other PCs.