Ulfgeir
Hero
For my group knowing the rules, is know the basic stuff and how your most common attacks/powers work, then look up the specifics if need be.
My group we play a bunch of different games (and a lot of games with similar rules), and have played together for years and years (thus having gone through a large number of games), so for us it is more a question of how did that specific rule (for example grappling, critical hits) work in THIS game, as there are tons of small subtle differences even if they have the same engine. That kind of stuff is usually things we need to look up when they happen.
But then again, it is seldom that a player leaves and a new player comes in (we are already 7 players + 1 gm for every game we play), and have always 2 or more campaigns running at the same time, alternating between sessions (Right now for example D&D 5e, Starfinder, Scion 2e, and more that are on hold like Star Wars and Legend of the 5 rings 5e, Exalted 2e).
My group we play a bunch of different games (and a lot of games with similar rules), and have played together for years and years (thus having gone through a large number of games), so for us it is more a question of how did that specific rule (for example grappling, critical hits) work in THIS game, as there are tons of small subtle differences even if they have the same engine. That kind of stuff is usually things we need to look up when they happen.
But then again, it is seldom that a player leaves and a new player comes in (we are already 7 players + 1 gm for every game we play), and have always 2 or more campaigns running at the same time, alternating between sessions (Right now for example D&D 5e, Starfinder, Scion 2e, and more that are on hold like Star Wars and Legend of the 5 rings 5e, Exalted 2e).