For those of you who don't remember or are unfamiliar, the Caller was a player job in the same vein as Mapper. Instead of being the player with good spatial sense, a pencil, and a pad of graph paper, they were the player with good organizational skills, a projecting voice, and a knack for reaching compromise.
It was the Caller's job to listen to the party when the Dungeon Master had presented them with a choice, get a sense of the group's opinions and reasoning, suggest a unified course of action, and then report that action to the Dungeon Master once something resembling consensus had been reached.
The Caller was also originally responsible for tracking player-character actions in combat, at a time when players were expected to commit to an action before initiative was rolled, and lose that action if it became irrelevant or impossible during the course of the round! (That rule really sped up combat, but at a pretty severe cost in fun.)
For some reason the concept of the Caller seems to have fallen out of contemporary D&D. I hear a lot of Dungeon Masters talking about co-DMs, or assistant DMs, or even just players monitoring the party's initiative track, but generally these roles seem to be about assisting with combat or narrative flow, when I think the Caller's greatest advantage was the impact they had on session-to-session party choices. The Caller also had no Dungeon Master knowledge of the campaign, which was a major consideration.
Investigate the mines or the sewers? Torture the prisoner? Trust the NPC? Right or left at a T intersection? Every Dungeon Master knows that these questions can stop a group cold for valuable minutes. They can try to guide the party through the decision, but it can be a tightrope. On the one side, the party is reading every word for hints about what lies ahead. On the other, there is inherent bias toward directing the PCs at the more interesting choice.
Combined, these two risks virtually guarantee that some decisions will be impacted by metaknowledge of the campaign. Having a player mediate these decisions is valuable not only to a Dungeon Master's peace of mind but to a party's organic enjoyment of the campaign.
I bring this up because I was recently lamenting to one of my players that our current group could use a Caller, and I was surprised to learn that he was unfamiliar with the concept. He is not much younger than me but entered the hobby later in life and through Palladium rather than TSR products.
Upon explaining the idea behind the Caller, he reacted with a revulsion that genuinely surprised me. At first I had a wrong sense of why he was upset, and tried to explain that 'Calling' isn't an in-character task. While it is certainly possible that the Caller's character is also the party leader, this isn't a requirement, so naming a Caller is not equivalent to making one PC dictator for life.
But my friend corrected me, saying that he understood the concept but that he couldn't imagine trusting a fellow player with that kind of control. This floored me, as I'd never considered that someone might perceive the Caller as being "in control." I had stated that the Caller was occasionally responsible for forcing the party minority into a choice when there was no agreement on a path forward, but doesn't that happen anyway, only much more slowly, without a Caller?
What worried my friend was that a Caller with a bias could exclude individual players from participating in the campaign. I see the risk, but feel like such behavior would be transparent, and would lead to censure of the offending Caller, if not removal from the group! It would be a simple enough matter to rotate Caller responsibilities, to avoid even sensible players developing an undesirable ego about their role in the group.
Of course, the flip side of that compromise is that just like most parties have a born Mapper, most parties also have a born Caller, and by not utilizing them a Dungeon Master is not taking best advantage of his resources.
All in all, I think my opinion on the value of a Caller still stands, despite this new perspective on the risks of assigning one. They provide a valuable service not only to the Dungeon Master but also to their fellow players, by keeping play moving through decision points rather than bogging down in minutia and disagreement. Not every group needs a Caller, of course, but I imagine there are quite a few struggling along without one.
But perhaps I spend too little time playing to see why the Caller might rub the other players the wrong way. I'd be interested in hearing feedback from other Dungeon Masters and players about whether they are currently utilizing a Caller in their games and how beneficial or detrimental they feel the role is to play.