Well, I'll point out three ways Players, and only players not DMs, have to follow rules that NPCs, and DMs, never do in most traditional games:
1. The player can not alter or control game reality. The DM can. A player can't just say "oh whatever my character kill 100 great wyrm dragons and loots all their treasure hordes! Ok, DM describe all my loot to me!" The player is free to try and do that, in the game play, but they can't just alter game reality. The same way a player can't say "oh...my rich dad npc gives me a million gold coins!", because the player does not control what the NPC does.....but the DM does.
2.The player can not create and add things to the game on a whim: they must do nearly all such things by the limit of their character. The DM can do anything on a whim. A player during the game can't see a dragon and say "My character has a +10 sword of all dragon slaying". A player playing a character in a game can not just 'wish' for everything at will....if they did so there would be no game. The player can have thier character look for and find a magic sword in the game play....if they have the right skills the character might even be able to make the magic sword. But that's it. The DM can just say an orc has a magic flaming sword or anything else on a whim.
3.The player can't control large groups of game characters. Sure there is a game style or two where a player has say five player characters or something like that. But most games the player has total control over just their single character. So a PC can't 'just say' they have five 'character allies' of the same level that follow them around and help them in all ways. Some games, like 3.5E D&D had Leadership where the player could follow all sorts of crunchy rules to get a small group of followers. A DM, of course, can 'just say' 11th level wizard Bob and 11th level cleric Joe are allies on a whim. And they can have any monster(s) in the book as allies, servants or whatever : basic adventure designee says so. .
So a player can play the game and go on an quest to find a moonblade and then their character can use it. But the DM just says "NPC Elor has a moonblade". And sure, the DM can chuckle and say "oh Elor went on a quest to find his moonblade too". Not that it matters....as it never happened.
The player could try to slay the great wyrm Fazootkii during game play. The DM can just say Dragnslayer Zombuo slayed the great wyrm Fazootkii.
And so on....
1. The player can not alter or control game reality. The DM can. A player can't just say "oh whatever my character kill 100 great wyrm dragons and loots all their treasure hordes! Ok, DM describe all my loot to me!" The player is free to try and do that, in the game play, but they can't just alter game reality. The same way a player can't say "oh...my rich dad npc gives me a million gold coins!", because the player does not control what the NPC does.....but the DM does.
2.The player can not create and add things to the game on a whim: they must do nearly all such things by the limit of their character. The DM can do anything on a whim. A player during the game can't see a dragon and say "My character has a +10 sword of all dragon slaying". A player playing a character in a game can not just 'wish' for everything at will....if they did so there would be no game. The player can have thier character look for and find a magic sword in the game play....if they have the right skills the character might even be able to make the magic sword. But that's it. The DM can just say an orc has a magic flaming sword or anything else on a whim.
3.The player can't control large groups of game characters. Sure there is a game style or two where a player has say five player characters or something like that. But most games the player has total control over just their single character. So a PC can't 'just say' they have five 'character allies' of the same level that follow them around and help them in all ways. Some games, like 3.5E D&D had Leadership where the player could follow all sorts of crunchy rules to get a small group of followers. A DM, of course, can 'just say' 11th level wizard Bob and 11th level cleric Joe are allies on a whim. And they can have any monster(s) in the book as allies, servants or whatever : basic adventure designee says so. .
So a player can play the game and go on an quest to find a moonblade and then their character can use it. But the DM just says "NPC Elor has a moonblade". And sure, the DM can chuckle and say "oh Elor went on a quest to find his moonblade too". Not that it matters....as it never happened.
The player could try to slay the great wyrm Fazootkii during game play. The DM can just say Dragnslayer Zombuo slayed the great wyrm Fazootkii.
And so on....