A lot of people want their game to play like Critical Role. They understand that the popular stream is special for a reason, but they still want to play in a game like it. Now, I can't do anything about making you a professional voice actor with all the experiences and skills that come with it, but there are some habits the players in Critical Role display on the regular that we can all practice to make us better players. Oh yeah, most of these apply to me too.
1. No Arguing With The GM
One of the more refreshing things about Critical Role that lets them run the game so smoothly is that the players don't argue with the GM. Yes, some discussions have happened. Yes there has been confusion over how spells work. However, by and large when Matt Mercer makes a ruling the players accept it and move on.
The key here is trust. The players trust Matt to run a fair game, and to run a fun game. They also trust him to look things up after the game and to own it if he makes a mistake. Ultimately though, they're there to play and have fun. So let the GM make a ruling, and be done with it.
2. Show Up To Play
Part of this is helped out because Critical Role is a broadcast show, however all the players show up to play. They have some cross talk and jokes, but by and large they keep their focus on the game while it is playing and do their non-game talking during the break, before the game, and after the game. This may be harder or easier depending on the group, but the more your game time can be focused on playing and nothing else the more game you're going to get out of it.
3. Be Other Players' Biggest Fan
Part of t his showing up to play is that it's clear watching Critical Role that the players are all the biggest fans of the other characters. They are there to play their character, yes, but they're also there - and just as much I'd wager - to see everyone else's character's story play out.
This isn't about just staying quiet when the focus is on other characters. It's paying attention like getting to watch your favorite show. This may be the hardest on the list. Some characters' stories may just not interest you, but the more focus you can put on other characters' stories the more enjoyment you can get out of the session. Which can be just awesome.
4. Make Your Character More Than Just Stat Blocks
What makes the characters in Critical Role so beloved has nothing to do with the stat blocks or how the characters handle combat mechanics. Trust me, it's definitely not how well they know the game. It's because their characters are fleshed out as people.
More to the point, they express these aspects of the character. You get to see Jester's childishness, Caleb's geekery, Beau's DGAF, Molly's charm, and so on down the line for all the characters. They take every opportunity to express themselves as characters from how they question guards, to how they interact with each other. They throw in these small moments and they let them play out, and in the end you don't have a group of characters on paper, but characters that feel like real people.
This realness extends into how they handle problems. They don't necessarily try to overcome every obstacle. They let themselves be afraid if the character would be afraid. They let their characters have flaws, and they are fine to play out those flaws. It's part of making the character real.
5. Try To Have A Good Time
The last bit, try to have a good time. Let the emotions of the game flow through you, but ultimately, be there to enjoy the game of D&D you have before you. Every game has flaws. Every game has strengths. Enjoy those strengths. Accept the flaws for what they are. Let yourself enjoy the game for what it is. You might be amazed at how much fun you have.