I think the Big Point is Role Playing vs Rules.
A lot of Gamers play a RPG just like any other game and use the mechanical rules. If you want to do any action in the game, you must have mechanical rules to do so.
Then there are the Other Gamers, the ones that put the Role, in Role Playing. The ones that leave the rule mechanics on the page, close the book, and role play. And you can Role Play anything.
A easy way to tell the two apart is any action that happens in the game play that has no mechanical rules attached to it. An NPC does a trick to deceive the PC, but with no rule mechanical effect the player will just sit there and say "whatever, um, guess my character is upset?" The same is for most lite effects. The orcs surprise the PCs, so the characters get a -1 on rolls just like page 11 says and the player just plays the game like they would with no "surprise".
Then you have the Role Players. When a NPC tricks and deceives the character, the player will role play their characters response to that. So the upset character might rush right into an obvious trap, that the player role players the character missing in the characters blind rage. Or a surprised character might drop their weapon and disarm themselves.
In a good game this is 50/50 between the DM and players. So players will take role playing actions and live with the effects willing, but also be subject to actions the DM does to the characters.