Disclaimer: I am relatively new to dnd.

I have played similar games in the past (Talisman being the most comparable) and have noticed that after a game of familiarization which is essentially scrapped later, people do a much better job in the future. With this being said, I understand 4-6 is the most normal and feasible to actually complete campaigns, but what about playing for those who have an interest but want to make it more of a "party-style game"? I have read that in instances when you have 8-12, that limiting factors such as races available for character creation, time limits on actions, having someone act in a facilitator mode in addition to the DM (just to remind the next player that they need to act soon), etc. are incredibly helpful. Just hoping for some insight from what people have seen works, or even just ideas as to what they think would help. Any and all information is appreciated, thanks!

Expanding on what Lyxen said, the downtime issue is likely to be worse than expected under real world conditions. The longer people wait for their turn, the more likely they are to get distracted. A few will hog the spotlight, and others will sink into the shadows. People wander off, lose track of what's going on, get bored, etc.

If you want a D&D "Party-Style" game, then I recommend Munchkins, Dungeon Mayhem, or other such fast paced card games.

Otherwise, you'll probably need to restrict yourself to 3v3 or 4v4 arena style tournaments, where the pacing is controlled, and you can set a time limit for sudden death. That will help the players retain their focus, and give the non-players a break without impacting the others. Anything with a real narrative will struggle.

Aside from operational issues, D&D is balanced for certain party sizes. 8-12 players represent 2-3 times more players than normal, which means that party performance may swing wildly. Most encounters will become shooting galleries, and if you try to balance it by bumping up the difficulty, there is a very high risk of TPK, as many higher level monsters are designed with the assumption that players will have access to higher level abilities.

I've run a group of 8 while DM'ing for my local game store, and I will tell you that Lyxen is absolutely right.  The larger group size really slows down gameplay, especially in combat, and especially if your group isn't fully prepared to act on their individual turns.  The game relies a lot on individual moments, so imagine in a party of 4, you act for 2 minutes and wait 6.  now imaging you are in a party of 12 and act 2 minutes and wait 22.  In a 4 hour session that means you have only acted for 20 minutes...vs an hour for the smaller party.

I would have to imagine running a group of 12 to be a literal nightmare.

Not to pile on, but the math is even worse than icon suggests, because the DM will take a turn as well, further diluting the amount of time any one player is active (unless you count occasionally recording when you take damage and maybe taking your reaction as being active). It just seems like begging for people to have side conversations and start scrolling Instagram.

And then out of combat, having 10 people try to have a conversation with one NPC seems awkward at best, a shouting match at worst  

And from the DM side, the number of enemies you’d need to run to make a combat interesting against a party of 8 or 10 or 12 PCs would be nuts.

Makes perfect sense, thank you all for the ideas. I like the other game suggestions. I think it would be best to just do that, then judge who is actually interested in a smaller group campaign and proceed from there. Great suggestions, I’m enjoying the community so far! Also if any of you hear of or happen to have an extra slot for someone new, hit me up. Either way, greatly appreciated!

Also the double DM suggestions, wouldn’t have thought of that. Many thanks!

Yeah if the primary issue was that  I had 8-12 people who wanted to play D&D, I'd try to run two different groups.

But if the issue was that I wanted to have D&D at a party with 8-12 people at a party or something, I think 2 groups and 2 DMs would be ideal. Start together at the entrance to a dungeon or something, then split up and continue at two different tables. Most of the time they'd be separate games, but you could include ways for the parties to communicate at certain points with puzzles or traps that required the groups to coordinate. Maybe at the end one group fights the lich and the other fights the guardian of its phylactery or something. It could be a lot of fun to design two parallel adventure paths for that.

All great suggestions, I played a 5 player party once and three players were doing it by zoom and it was pretty painful ( players sitting around waiting for their turns , other players hogging the spotligh etc.) although if the players were all in person and players let other players have their own time to shine it would be fine, I usually play with two other people + the dm, but all in person 4-5 person party could be quite comfortable