In boardgames this becomes a critical aspect of the design, sometimes accepted by the designer and sometimes neglected. When it's neglected, a group will often develop house rules.
Case in point, Monopoly. It is typically expected that all players keep their focus on the table while the game is being played...even when it's not their turn. This is reinforced by a house ruling that states a player must specifically ask for the rent when another player lands on their property. If a reasonable time-frame passes and the active player either rolls again (due to doubles), or passes the dice to the next player, then the opportunity to collect rent has passed. It's a crude version of what I'm thinking about but it fits as a basic example.
In a game of poker, you watch the faces of the other players while they play out their cards...trying to pick out the 'tells' that might indicate a good or bad hand. Similarly when it's you're turn, you try to avoid revealing those 'tells' to other players at the table.
In an RPG it's a bit trickier. The situation of waiting for other players to finish their turn comes up most commonly in two situations:
- when the party is split
- during combat
Most games don't seem to see the need for addressing this issue. But all too often I've seen players get bored and games drift into incohesion when half of the table is getting bored because they aren't active participants.
I've seen a few ways to resolve this issue. Few in the formal rules of a game, most in the form of house-rulings.
One of the common house rules I've seen in a few groups comes when the party splits. In these situations, the active players face NPCs portrayed by the inactive players. When the time comes the other half of the party to be handled, the roles swap.
While Munchkin isn't specifically a roleplaying game, it does have an elegant way to keep players active when it isn't their turn. As a card game, where players use their cards to modify strategies in conflict against monsters, many of the cards in the game can be played on your own character or can be played on others. You can thwart someone's defence against a savage beast to prevent them gaining an edge, or you can give them an advantage in exchange for a favour later on. You even can choose to assist another character directly if you don't have the cards in your hand to make a difference indirectly. At almost any time, all players are able to jump in on the action...it's their deliberate choice to join in or remain aloof.
I use something like the Munchkin method in my game "The Eighth Sea". Every player starts the game with four playing cards (two red, two black), and while it isn't their turn they may use these cards to modify the actions of the active players while they are passively observing the story. Red cards make actions easier for active players, and black cards make things harder. Once the cards have been applied, a player receives random cards back in their hand until they regain four cards. It helps to keep players alert to what is happening in the story.
Anything that keeps players invested in the activities of the story ensures a smoother running session. Less breaks in the thought patterns mean that the shared imaginary construct of the game world remains more stable.
In a similar vein, I also like it because I've sat around in too many games for an hour or more with nothing to do while a small group of other players have slowed the whole session with their time-consuming combat. I've looked at the frustration in the GMs eyes, they know that half the table is bored to death, but they can't get back to our side of the group without breaking the continuity in the combat, and risking those players getting bored.
Having this sort of mechanism written into the rules of a game also helps to spread out the burden on the GM when other players have the ability to adjudicate or provide assistance in the narrative.
Some players don't like to help out the GM. They see roleplaying as a semi-passive activity where they are provided entertainment by the GM. They enjoy it when the party splits, because that means they can get up from the table for some food or a rest break.
Keeping players active through down time activities means they are unable to break their concentration. This can lead to mental exhaustion, especially when a session lasts more than a few hours.
Another issue comes when this sort of mechanism meets an old-school rail-roady GM. The kind of GM who likes to make sure he has control of all aspects of the story, allowing for minor deviation in plot if the die rolls go in an unexpected direction (I say 'he' because virtually all of the GM's I've encountered who follow this style of play have been male). This type of GM doesn't like the input of other player/GMs, perhaps believing in the adage that "too many cooks spoil the broth".
Generally, I like the idea of a game mechanism that keeps players active for more of the time. I can see why certain players probably wouldn't like this sort of thing added to their game.