Tacky?

Meegles4

OP, Leisel expressed exactly what I was thinking. Your invitations describe the tone of your wedding, so if you want it to be a bit more "formal", you need to make your invitations a bit more formal looking.

I also agree a wedding website can help you here. You can include an "itinerary" of sorts that mentions the timing of everything and what will be available to do at the reception.

I would not expect people to change for your wedding, unless this is common in your circle or you have a gap between the two and everyone is local (and thus, can go home and change). Likely, if I were a guest I'd wear a sundress or maxi that's both appropriate for a wedding and comfortable for an outdoor reception. I would probably wear nice flip flops or sandals and a change of shoes is perhaps the only attire change I might bring. 

As for the cash bar, I have no good solution on wording that because those are not common in my circle and as PPs said, it's rude to put that on the invitation. IMO, (which I know you don't want anyway), you should actually nix the cash bar and just offer what you can afford to host. If that's just some beer in buckets, that's fine. If I were going to a park wedding like you're describing, I would be fine if I found that there was only beer, wine and soft drinks. I wouldn't be expecting Manhattans.

julibug86

My friends got married last summer and they are very non-traditional in general.  They had their wedding in the field where they play Ultimate Frisbee (and fell in love) with the reception at a nearby outdoor venue.  She struggled with trying to let people know that it would be a casual wedding, while still holding on to some traditional items (dances, speeches, etc.).  In the end, many of your friends and family will (should?) be excited for your wedding and will ask you about it.  When they ask, try to casually mention the  lawn games and the option of changing clothes.  For the wedding I attended, I wore a sundress and opted to play volleyball in it, but did change later into comfortable clothes (there was a giant Ultimate Frisbee game, but I got distracted drinking and talking). 

As for the bar, with daytime (I'm assuming it's daytime because of the outdoor games?), the open bar might be cheaper (or maybe you could do a wine/beer option?  or set a cap?).  My friends had a relatively low alcohol cap, but since they both don't drink and everyone was running around so much, we didn't even come close to reaching it. 

[Deleted User]

In Response to <a href="http://forums.theknot.com/Sites/theknot/Pages/Main.aspx/wedding-boards_etiquette_tacky-11?plckFindPostKey=Cat:Wedding%20BoardsForum:9Discussion:9da399cd-5e36-42b8-a691-3ac781055e3bPost:2ffaf573-f800-48d8-8e94-d591196fd1aa">Re: Tacky?</a>:
[QUOTE]We are having a sit down buffet style dinner.
Posted by eadimoff9432[/QUOTE]
There is no such thing. It's either sit down, or it's buffet.

MangoSong

[QUOTE]In Response to Re: Tacky? : We are having a sit down buffet style dinner.
Posted by eadimoff9432[/QUOTE]
There's no such thing. Sitdown is where you are seated and served. Buffet is where you do down the line and pick your dinner. Cocktails, if that's what you were thinking, people go around with trays and while there are usually a few scattered tables, it's mostly standing room.