The cabbie's making conversation, he's told you that work's been a bit slow today, and traffic was bad on the way to the airport, where he picked you up. Outside the grubby windows, implausably tall, gleaming skyscrapers disappear into the clouds, the sun flickers in the corner of your vision, a nearby suspension bridge's symmetric struts interrupting its gaze.
"You new around here?" He says, off-handedly.
You've only been playing the game for half an hour, this still feels like the playable intro. He's implying you are in the way he asks, but the UI brings up a discreet overlay - 'yes' or 'no'. Its the first time you've had a choice in dialogue from your otherwise silent character.
He's expecting a response. Smiling at the fact of it:
"Yes", you reply silently. Look out of the window again, "brand new" you think.
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A single optional choice dialogue, what the NPC responds with is appropriate, but only a line for either choice. In a sense, it's rhetorical, in that the actual choice is non-concequential. What's important is that the player thinks about the question for a second. And in a sense, that choice defines a binary attitude to the game that may stay with them. Bright eyed, hopeful, excited 'yes', or jaded, disinterested, deceptive, experienced 'no'.