Is a cash bar at an engagement party tacky?

I've never been to a hosted party with a cash bar. That being said, this isn't necessarily a situation where guests can byob. If you don't want to pay for people's alcoholic drinks, don't. Just let your guests know beforehand. Engagement parties aren't necessary either. Congratulations!

I don't think it's nice to invite people to parties and then have them open their wallets. Engagement parties aren't necessary (and especially so if you can't afford it), but if you insist on having one, have it in a more inexpensive location so you can host all your guests with adequate food and beverages.

A lot of people consider it rude when the couple throws their own engagement party because these are usually hosted by the couple's loved ones, if at all. If there is an engagement party then the entire party should be hosted, including the drinks. Also, only people actually invited to the wedding should be invited to the engagement party.

I'm going to take what is apparently a non-majority opinion here and say no, not tacky. You are paying for the tickets and entrance to this premium space. There will be entertainment provided. I think you are fine, as long as you mention the cash bar up front. If your conscious or etiquette sticklers on here get you down, you could always consider buying 1 drink per person and the rest are on them. Providing food and beverages is perfectly adequate. People don't always need a full open bar, and I'd say this is one of those occasions

I was initially going to say it was tacky until I saw it’ll be at an MLS game. I think people going to a game that’s also an engagement party might expect to pay for alcohol. If it were at someone’s house or a restaurant I’d say it would be better to provide drinks.

If the pricing of the open bar is something that you and your FH can handle, I'd say the open bar is the way to go. However, if it's outrageous you can simply tell them we looked at that option but would prefer to be able to offer that at our wedding instead. Love the idea of it being at the game though!

I don't think it's tacky since you're supplying them with food and non-alcoholic beverages. I don't understand why alcohol is treated like such a necessity when hosting events. If your guests require it to have a good time I think they should be ok paying for it.