Joystiq - What Makes a Classic RPG?

Joystiq's Rowan Kaiser writes his usual weekly RPG column, examining the idea that "isometric" equals "old school". His methodology is hit-and-miss -- but then again, it's hard enough defining the concepts:

In the past few weeks, I've noticed a few different sources that have used isometric perspective as an indicator of classic role-playing games. First, GOG.com advertised the new throwback RPG Inquisitor by saying it was "true to the isometric roots of classic PC gaming." Then Obsidian's Project Eternity Kickstarter heralded its isometric perspective regularly.

I found this focus on perspective to be a little confusing. Certainly I love Diablo and Fallout and other isometric RPGs, but the genre has such variety in it that focusing single components seems narrow. But what if I was wrong? What if classic RPGs actually are almost all isometric, or turn-based, or story-driven, or open-world? What if there isn't that much variety after all?

So I decided to test my theory that classic RPGs come in a variety of flavors. I made a list of the most important and famous western, non-massively multiplayer role-playing games – which spanned 50 titles. Then I looked at the components that usually distinguish RPGs from one another: perspective, combat style, complexity of character development, story importance, whether there are puzzles, geography, and how the game provides the character(s) you control. What I found is that the RPG genre is not easily categorized. What I found was a genre filled of diverse titles.