Translate Tabletop Roleplay Jargon For A First Timer

You said yes to a roleplaying game before thinking it through, and now you are picturing an evening of amateur dramatics with strangers. This explains what a session actually involves, how dice rolls work, and what is genuinely expected of you, so you turn up prepared rather than braced for embarrassment.

<context>
Someone has been invited to join a {SYSTEM_NAME} game and has never played a tabletop roleplaying game before. They are worried about not knowing the rules or having to act.
</context>

<task>
**Translate the jargon and expectations into plain terms:**
1. What actually happens at a session: who talks, who rolls dice, what the game master does
2. The core mechanic in plain terms: how a dice roll decides an outcome
3. What a character sheet is and only the parts a new player needs to understand for session one
4. Reassurance on the "acting" worry: what is actually expected versus what people imagine
</task>

<output_format>
- Four short sections matching the numbered points
- A five-item "what to bring to your first session" list
</output_format>