Themed adult parties, like children's parties, add extra fun and excitement to a birthday celebration. The medieval age is remembered for knights in armored suits, fair maidens, elaborate feasts and drunken festivities. Bring the medieval theme to your next adult birthday party and allow guests to enter an ancient world for a night.

Write the invitations by hand using calligraphy pens on parchment paper. Roll each invitation into a scroll. Seal closed with a wax seal. Word the invitation with Old English phrases such as: "Hear Ye! Hear Ye! Noble knights and fair ladies, the honor of your presence is requested."

Incorporate common medievalcolors into your decor, such as red, purple, yellow, silver, blue and green. Create a drawbridge using plywood and chains so that when guests enter, they feel like they're walking into a castle. Set up a large chair covered with plush pillows and call it the throne, where only the birthday boy can sit. Place torches outside to light the outdoors or walkways. Hang swords and shields on the walls. Set out a treasure chest full of foil-covered chocolate coins.

Hire an artist to draw pictures of guests. Have a juggler roam around the venue. Do square dancing as a group. Have a magician put on a short show or have an acrobatic dance team perform for the crowd.

Serve food that can be eaten without silverware on pewter-colored plates that look medieval. Try chicken wings, corn on the cob, baked potatoes, loaves of bread, and a plate of cheese and fruit. For drinks, fill a large cauldron with ginger ale, apple cider or an alcoholic beverage.

Ask everyone to dress for the party according to the theme. Some ideas for costumes include jester, knight, gypsy, farmer, bar maid, lady-in-waiting, monk, peasant and royalty.

If you decide to give favors to party guests, beer mugs and goblets are great choices. For added personalization you can engrave the date of the party, the birthday person's name, or the name of the guest.