Setting attire standards for your groomsmen and guests

Menswear may seem like a simple thing: just slap on a suit and you're good to go, right? Well, not exactly. The formality of your wedding day plays a big role in what the groom, groomsmen and male guests all will don on the big day.

Whether you're a to-be-wed trying to decide on the wedding party's attire or a guest getting ready to enjoy the celebration, this guide will help you know what's appropriate for any wedding.

“As a guest, paying attention to the dress code is essential to making sure your attire fits the venue and theme, as well as the bride and groom's overall vision,” says Bruce Hershey, vice president of marketing for Men's Wearhouse. “You don't want to be the guy in a khaki suit and sandals when everyone else is wearing tuxedos. Unless you're the bride or groom, your goal is not to stand out with your clothing, but to dress appropriately and have a great time.”

And that means decoding the dress code on the invitation. A few simple words will tell you everything you need to know to look like a dapper dude, not a dud.

Black Tie. This one is pretty easy. Black tie means you wear a tuxedo, preferably a black one. The goal is to keep it neutral, sticking to black and white, says John Roberts, manager for American Commodore Tuxedo. Black bow tie or straight tie, black or white vest, black shiny shoes. It's classic. It's cool. It's hard to mess this one up. Don't own one? You can rent—just be sure to plan ahead, especially if the wedding takes place during spring, summer or fall, when shops will be busy with prom and wedding rentals.

Black Tie Optional. Here you have the choice to take that tuxedo stripe or leave it. You won't be overdressed if you opt for the classic tux, but you can also get away with a sleek black suit. Not sure how to tell the difference? Roberts notes that tuxes have a satin finish; suits do not.

Semiformal or Cocktail Attire. You'll want to rock a suit or dress slacks and jacket, but you can roll in a wider range of colors for this gathering. “If the wedding is during the day or outdoors, you can opt for a lighter-colored gray or blue suit. If [it's] indoors or in the evening, choose something in a darker gray, charcoal or navy,” Hershey suggests. A tie or bow tie is appropriate.

Festive Attire: OK, even we will admit this one can be tricky. Consider it much like cocktail attire with some added punch. Couples tend to steer in this direction when they want the wedding to have a lighter, more fun feel, so incorporate brighter, more vibrant colors, Roberts suggests. Colorful or patterned pocket squares or socks are popular ways to add some more personality to a guy's look, he says, as are adding fun tie bars.

Beachy Formal: An oxymoron? Nope—just because a wedding is on the beach, it's not an invitation to show up in your Speedo. Linen slacks in tan or a lighter gray are popular for beach weddings, Roberts says. A jacket is optional, and leave the tie at home.

Casual Attire: When an invitation says casual, you still want to dress up a bit. After all, it is a wedding. So leave the shorts at home and opt for a pair of dress slacks and a button-down shirt, preferably with long sleeves, Roberts says. When in doubt, think about what you would wear to church.

So now you know how to decode the dress code on the invitation. But what if there is no dress code explicitly stated? No need to go into a full-blown panic. Put on your sleuthing cap and look for some clues in the invite.

First, check for a wedding website, which often has a wealth of information that won't fit into the invitation itself. If there's no URL, pay attention to the timing and location of the event: If the wedding is outside during the day, chances are it's a more casual or semiformal affair. If it's in a fancy ballroom on a Saturday night, it is likely a more formal affair and a dark suit should be appropriate. “If there's no dress code stated on the invitation, a suit is always a good choice,” Hershey says.