Board Games
Board games are a safe game choice when looking for ideas for 18-year-olds, with many appropriate for all ages. Choose a classic board game such as Monopoly and Life, or one that's more modern, such as Apples to Apples, which uses cards printed with adjectives. One player acts at the judge and turns over a card with a noun, while the other players try to choose the best adjective card to play with the noun card. The judge decides whose adjective is most appropriate. For example, if the noun card was duck, the other players might play the cards white, animated and tasty. The judge would determine which adjective best describes the duck.
Card Games
Card games often are something teenagers will play because so many options exist. Card games can be focused for as few as one player, such as solitaire, or for a group of players, such as poker. Classic card games, like Texas hold 'em or blackjack, require a standard playing card deck of 52 cards. Other games, such as euchre, use a modified deck. Some games come with their own decks of cards, such as Uno or Phase Ten. Card games have the advantage of usually being quick and easy to learn and play.
Physical Games
If you want a more active game option, consider playing a sports-based game. For example, if you have a few players, play pickup basketball. A larger group allows for a game of touch football. If you have access to a playing field or a large open area, play baseball or softball. If you are not interested in classic games, try more modern games, such as disc golf. Disc golf is a game where players throw a flying disc into a goal to score points. Some communities offer courses, or you can design your own. Another modern classic is corn hole, which uses two wooden boards with holes as the goals, set apart from one another. Players take turns trying to throw bean bags into the holes to score points.