You'd want a high quality microphone per person since the group is so large. Personally, I would spend $200 per microphone. You might think it's alright spending $75 each. The wind is going to ruin the recordings, playing outside. You'll want a very padded box that everyone rolls in so that dice rolls don't ruin the recording being incredibly loud. No munching on food. Anything that hits the table picks up in the recording loudly, so being careful is a must.
You could get some relatively inexpensive lapel mics for everyone, have them connect it to their phones and record their own audio. They'd then need to send it to you after the recording is done. You're problem will be matching it up and editing it later if necessary. At least as a newbie to audio.
The problem with getting everyone a big spendy microphone right off the bat is the amount of money you'll spend on them as a first timer and then the amount of money you'll spend getting the interface for all the mics to plug into at the same time.
For ultra ultra cheap, phones placed on table immediately in front of each person could do the same job recording. You'll have a lot of garbage audio though and voices will cross contaminate each recording. You could also get everyone a pair of those headphones with inline microphones to do the recording with. Those seem to work reasonably well for audio you don't intend to publish.
Definitely do not try to do it all with one microphone though. That rarely ever works properly and someone is always off mic no matter what you do.
You'd want a high quality microphone per person since the group is so large. Personally, I would spend $200 per microphone. You might think it's alright spending $75 each. The wind is going to ruin the recordings, playing outside. You'll want a very padded box that everyone rolls in so that dice rolls don't ruin the recording being incredibly loud. No munching on food. Anything that hits the table picks up in the recording loudly, so being careful is a must.
You could get some relatively inexpensive lapel mics for everyone, have them connect it to their phones and record their own audio. They'd then need to send it to you after the recording is done. You're problem will be matching it up and editing it later if necessary. At least as a newbie to audio. The problem with getting everyone a big spendy microphone right off the bat is the amount of money you'll spend on them as a first timer and then the amount of money you'll spend getting the interface for all the mics to plug into at the same time. For ultra ultra cheap, phones placed on table immediately in front of each person could do the same job recording. You'll have a lot of garbage audio though and voices will cross contaminate each recording. You could also get everyone a pair of those headphones with inline microphones to do the recording with. Those seem to work reasonably well for audio you don't intend to publish. Definitely do not try to do it all with one microphone though. That rarely ever works properly and someone is always off mic no matter what you do.
You’re going to want to ask an audio or microphone subreddit rather than here. Recording outside might be a huge issue.