When I say “playing off-sheet,” I’m referring to a couple of things: quantity of abilities and nature of abilities listed. A character sheet is a reference for the player to use to keep track of the tools available in play. That is, what mechanical aspects the character can bring into play. I think, in classic systems, there are limits to what can be found on character sheets.

One of the hallmarks of newer D&D editions and similar systems is the profusion of character abilities, many in the core rules and a greater volume in the expansions to be found. It seems at every experience level a character acquires yet more powers. These abilities are designed to be used in conjunction with other abilities to make for even greater powers inplay. The idea of a “character build” arose as a way to plan how to take a PC to superhero levels of power by planning out how to take advantage of combinations of feats during levelling.

That’s not old school. Old school development can involve getting new abilities as a character levels up, it certainly doesn’t involve a plethora of choices at each level–remember, the way to differentiate characters is in play–and combining them into a superpower. There shouldn’t be bunches and bunches of abilities for players to remember and to have to check how they interact.

There’s also the notion of players using sheets to find the Easy Button, some ability or group of abilities that automatically solve the challenge at hand without requiring the player to choose what to do. That sort of thing removes player skill from play, which is not part of the classic ethos; we want players to have to develop skill and make choices constantly to overcome challenges.

I see old school sheets as being bare references for players. The details of spells, inventory of equipment, notes and numbers that won’t solve challenges by themselves and instead provide info about the tools the player has available.