Proto rule zero

“Rule zero over the years”

That is a good article.

Though I think “rule zero”—in some sense—actually predates D&D.

On the Pied Piper forums; Mike Mornard, Rob Kuntz, and Gary Gygax talked about Chainmail games where rulings were made on-the-fly to deal with things players wanted to do that were not covered by the rules. Such as setting fire to the woods enemy units were holed up in. Mike in particular made the point that “what is not forbidden is allowed” was the way the Lake Geneva wargamers played before D&D.

Unfortunately, those PPP forums seem to no longer be online. (And the PPP forums may have had multiple incarnations.)