Some of my favourites for casual play :
-Dictionary : one player picks a word in a dictionary (works well with uncommon words that people are unlikely to know, but it works too with common words, technical words, etc…). Everybody write down a definition for this word and hand it to the player who picked the word (this player writes the actual dictionary definition) who reads them all. People generally try to write plausible and dictionary-like definitions, but you can as well write an implausible one, an humourous one…depends on your mood and strategy. Then each player try to attribute the definitions to their author. You gain points for each word you correctly attributed, more points for if you guess properly what’s the dictionnary definition, and even more when someone believes that your definition is that of the dictionary. I don’t remember how points are counted, but let’s say 1 point for finding out that Paul wrote the second definition, 2 points if you figured out the correct dictionary definition, and 4 points if Paul believes that what you wrote is the dictionary definition. If nobody guessed the correct definition, the player who picked the word get points (how many depends on how many players there is). Then another player takes the dictionary and picks a word. Might look like a tedious game from this description, but IME it’s great fun, especially with creative players.
-Customs, a bluff game. You need several packs of cards and monopoly money. Again, I don’t have the exact number of each card, so improvise. For instance, let one joker, two aces, 4 kings, 8 queens, 16 jacks, and about 40 low cards. One player is the custom officer, the other players tourists coming back home and trying to smuggle contraband. The jacks are for instance bottles of alcohol, the queens cameras, the kings expensive jewelry, the aces drug (or whatever other list of items you decide), regular cards are empty suitcases and the joker is the diplomatic suitcase. All players receive an equal amount of money. One player picks 4 cards (5? can’t remember), looks at them, and makes a declaration (truthful or not) to the custom agent, for instance : “I’m bringing one bottle of rhum”, or “nothing to declare”. The following can happen :
-the custom agent believes him. The player then pay him the import tax for the items he declared (say for instance 1 for a bottle/jack, 5 for a camera/queen, $ 20 for jewelry/kings, etc…)
-the custom agent doesn’t believe him and “search the suitcases” : the player shows his cards. If he said the truth, the custom agent apologizes profusely and pays him a fixed indemnity for the inconvenience. If he lied, the tourist pays the custom agent a fine for all items he was transporting (even the ones he had truthfully declared) of 3 times the regular tax.
-the custom agent believes him but the player to the right of the tourist (and only this one can do it) denounces him as a smuggler. Cards are revealed also in this case. If the player was truthful, the denouncer pays him a fixed indemnity for his calumny. If the player lied, he’s taxed as if the custom agent had disbelieved him, but half the money go to the denouncer.
Finally, the player can announce “diplomatic suitcase”. Again, the custom agent can believe him and let him go, or ask him to open his suitcases. In the latter case, if the custom agent was right (the “tourist” didn’t have the joker), the tourist pays a huge fine. If the custom agent was wrong (the tourist actually had the joker), he (the CA) pays the tourist the huge fine, and the tourist pays nothing, even if he had other valuable cards. If the custom agent believed him and let him go, the player must discard the “diplomatic case” and pick another to replace it (secretely. If he said the truth, he must discard the joker. If he lied, he just discards any card he wants. As a result, there might be several players during the game announcing that they have the “diplomatic suitcase”)
If the player had to open his suitcases, the next player to his right (the previous potential denouncer) picks 4 new cards, and becomes the tourist. If the custom agent didn’t ask the player to open his suitcases, then the cards are passed to the player to the right, who discard one (and shows it, which might give a clue as to whether the previous player lied or not) and picks a new one in the deck. It’s then his turn to declare to the custom agent what he’s bringing in.
When the deck is exhausted, another player becomes the custom agent, and so on until all players have been custom agent once. Whoever has the most money at the end wins.
-Finally werewolf/mafia games work well. You can easily find a set of rules for those, including on this board, since mafia has been played regularly here.