"Maybe D&D isn't for you..."

[Anonymouswizard]

Even twenty minute games tend to be played multiple times in an evening - a two-hour session sounds about right.

This is why one-shots and open table campaigns can help - the investment is much, much lower. That and games that don't require front-loading of a ton of rules.

I've played Apples to Apples derivatives for four straight hours before (in fact it's the only way I've played CAH). So yeah, I totally get what you mean about shorter games. The people I know who do regular board games afternoons/evenings generally run for four to six hours while playing two games, including multiple rounds of shorter games.

Personally I have no strong reason to hold four hour sessions specifically other than the fact that four hours is the minimum amount of work that will net a convention game master a free day ticket to the event. It would not surprise me at all if the standard originated from some event organization or organized play format.

It's also just a really good length for a weeknight game session. Savage Worlds points this out: you ask everyone to arrive at six, can be certain that everybody's turned up and has their food eaten or sorted by 7, and then stop at 11 so people can get home by midnight.