Ok... I'm not sure if you posted this as a test for the Critiques forum or if you're going somewhere with this text. Assuming you actually want some serious commenting, I'll get the ball rolling - after all, one of my great loves is roleplaying games, so the subject line caught my attention.
Cemero the Ranger paused and sniffed the air. There was a smell to the room, a familiar smell, the smell of a hated foe. An ancient enemy lurked near. Orcs!
I'd have liked to see some more descriptions here. In most RPGs, the DM/GM (Dungeon/Game Master) would describe the setting in detail to give the player(s) more information to use in the situation to come - is there any cover to be found, any light coming in from windows? What do the orcs smell of? Unwashed leather loincloths (eww!) most likely, possibly rusted weapons - and that only if the actual RPG setting sees orcs as the most common, usually very simpleminded enemy.
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“Roll for surprise!” yelled the Dungeon Master.
You already have an exclamation mark, no need for "yelled" in the text.
“I’m a ranger,” said Scott. “Rangers aren’t surprised by their ancient enemy.”
“Fine,” said the Dungeon Master, sounding disappointed.
“Roll for the orcs,” said Scott, “they might be surprised by me!”
“They’ve already seen you,” said the Dungeon Master.
“Did you roll for that?” asked Scott.
“OK, whatever!” The Dungeon Master rolled a die.
“Ha!” shouted Scott triumphantly.
The Dungeon Master shook his head with disgust. “You surprise the orcs, go ahead and roll your first attack.”
This passage sounds plausible to me, but I've been playing RPGs for 20 years. This dialogue has happened around my gaming table more times than I care to remember... But does someone who isn't into RPGs understand what is going on? If this is an excerpt of a longer text which explains RPGs, it could work. Otherwise I suggest adding some more information on the subject at the start of the dialogue, after you bring the reader from the world of Cemero to the world of Scott and his DM. Explaining what RPGs are all about to someone who doesn't know anything about it is difficult though, and I'd personally need a lot more coffee than I've had this morning to attempt to put it into writing myself.
While I didn't spot any direct typoes or grammatical hickups, I do think this text needs more work - and in case it is a small excerpt of a longer text that explains more, a comment about that would be welcome.
Edit: I've had a bit more coffee now...
I see some potential in this, but I'd like to see some more depth and conflict in the story. Is Scott living into his role as Cemero a bit too much? Does he feel annoyed at the GM for breaking his immersion? Could it be the other way around, does the GM get annoyed at Scott for being a 'rules lawyer'? Again, if it's just a small excerpt, you may have already thought about this, but it doesn't come across in these few lines.
