We're doing pizza and beer as well AT the venue, sitting on the steps of the amphitheater our ceremony is in... and then having the wedding party help us set everything up for the next day. Can't get much more casual than that haha
I think it should be hosted (maybe not EVERY drink, but certainly a few) but one of my favorite rehearsal dinners was in an upscale pool hall with pizza, beers and wings. Love it! (And if you can skip the rehearsal? Skip the rehearsal......just do the dinner....)
It def does NOT have to be fancy. Our rehearsal is going to be laid back and fun. very family style. The country club that we are having this at offers us different styles of buffets and we chose a kabob buffet. It is def going to be fun and relaxing.
I wouldn't say it has to be "fancy" exactly, but it should be a nice time and a way of showing your bridal party and the others there that you are grateful for all they have done for you and how much they still will be doing. I'd think pizza and beer would be fine so long as you make it somehow special for your guests so they don't feel as though the rehearsal dinner was just thrown together on a whim. Just one bit of advice - I'd make sure all of your guests like beer. I know I personally can't stand beer and would be a little annoyed if beer were the only option. Maybe have some wine coolers available also.