Boundaries - Boundaries... they exist.  Don’t encroach.

Feel the Scene - As a Player, you will want to shout out your ability and skill bonuses.  Don’t.  Use this as a chance to role-play.  Talk through the “who should do what” scenario.  Adventures are not completely dependent on one success.  So, even if the person to roll is not the leading expert in the party, let them at it.  Have fun.

Murder Hobo  - Adventures are designed to be immersive stories.  Players will know when killing is a preferred plan.  If unsure, ask.  As an example, having a simple bar fight in a city should not result in a death.

No Metagaming - One of the hardest tasks for a knowledgeable player is to not act on knowledge a PC would not know.  Please avoid these moments.  This is also a dangerous slippery slope.  Making decisions using out-of-play information could put a PC in a position that can cause more harm than intended.  Truths to be accepted:

Not all creatures encountered will be the ‘floor model’ found in the available core material.  There are many reskins to be encountered in this world.

When a PC acts as they should in a situation, showing common sense, even when ignorant, can earn the PC extra XP.  The game is not set up to punish but to create interesting situations for the PC to react as they would.

If a PC should know details on a subject, whether lengthy or cursory, the DM will share what they know prior to committing to a decision.  This is not a ‘gotcha’ game.

No PvP - Players will not attack or undermine other Players.

Player Time - Please be considerate of other players.  Allow everyone a chance to contribute.  Again, the game should be fun for everyone.  Not every player enjoys all aspects of the game - some compelled more by combat than role-play.  Fall to your strengths but embrace a chance to explore something new, not worrying about being judged.  Introverts and extroverts can find a balance and get just as much enjoyment out of the game in different ways.

Stay Focused - Be courteous to all by being ready for your Turn and not distracted while at critical parts.  Sure, the flow may abruptly change just before your Turn, making you have to rethink your next Action.  That is fine and expected.  Just know a running clock may be initiated to help avoid the game from stalling or sputtering.

The Final Answer - Knowing the rules is awesome.  But sometimes situations fall into a gray area.  The easiest way to decide... the DM has the final say.  Players are welcome to first quickly explain their reasoning, which can sway the final decision, but this will only be tempered with the idea of not stalling the game.