Who gets invited to the engagement party?
Everyone who is invited to the engagement party should ultimately be invited to the wedding. (If you don't invite engagement party guests to the wedding, they may wonder what they did at the first party to insult you!) There are, however, two exceptions to this rule: if your engagement party guest list will be significantly larger than your wedding day guest list, or if your party is being hosted by an outside party -- someone who has no idea who will be included on your wedding guest list.
If you're planning an intimate wedding for just family, but would like to celebrate your engagement with all your friends, by all means, have a big engagement party. Word will get out that your wedding is going to be family-only, and no one should feel hurt. Or if you have a well-meaning host who, for example, invites everyone at your office (and you have no intention of inviting any of them to your wedding), it's okay to stick to a smaller wedding guest list. Most coworkers should not be expecting an invitation to the wedding anyway.
See More: Engagement/Engagement Parties , Rehearsals + Brunches , Just Engaged?