Well, I mean, unless they don't. At my table, I obey the 'rules', but you don't have to. At what point are you no longer playing D&D?Ahh, well yes and no. The GM can monkey around with things all he likes prior to a campaign, and has a limited amount of agency to change minor things at the table sometimes, and only then by table fiat. He does not have the authority to use or ignore rules as he sees fit during play. Once you start playing the rules harden from suggestions into, you know, rules.