In doing my Game Chef reviews I was struck by the fact that the most complex game in my review cluster was the one with almost no mechanics. Complexity is an important barrier to new players and while not something to be avoided you want to stage to increase gradually. For more on that take a look at Magic the Gathering’s New World Order.
Of course a board / card game like Magic has a big advantage in understanding its complexity – it doesn’t maintain a shared fiction among the players in any essential way. In RPGs a whole level of complexity comes from crafting, tracking, and communicating the fictions of play. Communication can be especially awkward to consider in terms of complexity. We often use very broad chunks to describe hard learned communication skills, even in discussions of techniques meant to unwrap some of these elements.
One good way to estimate this kind of complexity is to consider everything a person needs to track to appropriately handle fictions in play. This includes established details and social cues and how crucial these are at each step. When establishing non-mechanical procedures for fiction, such as question games and prompts, it is important to limit the responsibilities of a player socially and fictionally to avoid an overwhelming coordination problem.
This is one advantage mechanical procedures have over non-mechanical ones, they are self-limiting in scope. Conversely answering open ended questions in the midst of unconstrained social interaction will either become exhausting or force players to evolve a more constrained procedure for handling this gap in design. People are fairly good at evolving these things, but they don’t do so automatically or uniformly – which makes games that rely upon this sort of unconscious adjustment less accessible and transferable without careful seeding by giving clear tools to build customized social and fictional procedures — the building blocks of a language of play.