How much rolling is too much rolling?

Courtesy of my roomate Austin, who is soon to be running his first game (Mage: The Ascension). When should a GM ask a player to roll? When is it okay to skip rolling? What does asking a player to roll for something mean to that player, dramatically?

So first off, the system you're using does matter for this. D&D for instance includes a specific roll for most of the things you can do at any given moment. If you get a railroad spike stuck in your head and roll D&D completely by the book, you will make your players roll for a hell of a lot of stuff.

However, why would you ever do that? Excessive rolling for inconsequential things bogs down gameplay considerably. The only time a literal action-by-action approach should be taken would be in the very first couple of sessions with a new system. Constantly making players reference key stats repeatedly will help everyone in learning their sheets. After those sessions however, I fully believe in a more 'less is more' strategy.

To better explain my view on this, a few basic guidelines.

1. A player should roll for anything that is opposed.

This one's obvious. Drama is based on this key rule - rolling to perform an action is harder that just doing it, duh. Kind of common sense.

2. A player should roll for anything that is challenging.

Building magic devices, pulling themselves out of knee-high mud, everything they have to expend effort to do. 'Cause it should be hard.

3. A player should roll for anything that has a variety of outcomes.

Here's one that's interesting. If character is attacking an opponent well below their skill level (someone easy to hit), you could choose to just auto-kill the mook. Or, he could roll for it, roll exceptionally high and murdericate overkill the mook. Even in a normal combat, you roll to hit opponents because of the nature of combat - it's terrifying because you don't know how fucked up you'll be by this next hit. Which leads too....

4. A player should roll for anything that is unpredictable.

Random effects are unpredictable and thus fun. Attack/damage rolls are unpredictable and thus fun. Ideally all rolls a player makes should lead to a variety of outcomes, degrees of success as it were. Thus be prepared to improv and handle serious actions your characters take with a variety of outcomes. So if they're taking those actions, they should roll for them.

5. A player should roll when it's fun.

There is simple mechanical joy in rolling well. Thus players should be given the opportunity to do so. So roll when your players really want to play a game, when words aren't enough and they've roleplayed for three hours and finally found a damn goblin band.

This is a much more cut-and-dry topic than my earlier ones, but important nonetheless. In truth, learning the perfect balance will take time - but if all else fails, here are some criteria to check.