Free Online Party Games That Work Instantly in Any Browser

Gartic Phone (garticphone.com) is a telephone-like game, suited for online play. Each player comes up with a phrase (e.g. "cat on a hot tin roof"). The phrase goes to the next player who is tasked with drawing that. Then that drawing is sent to the next player who has to describe the drawing. Then the description is sent to the next player who draws it. Repeat until you get back to the first player or to a certain number of rounds. At the end replay all of the transitions to great amusement.

The second that I think would work well is Liar's Dice. Each player is given 5 dice. Roll the dice and each player can only see their own dice. Players then take turns bidding on how many dice are on the table (collectively across all players). Bids must either increase in count, or keep the count and increase in number. e.g. if I bid five 4's, the next player could bid six 2's, or five 6's, but not five 2's. Any player may challenge the last bid at any time. Once challenged, all dice are shown, and whoever is wrong (the challenger or the bidder) loses a die. Losing becomes a vicious cycle; the more you lose the less information you have, making it more likely for you to lose. As an option (but one that I think makes the game better), any die rolled as a 1 is wild and counts as all other dice.