Keyword is a game where a player has to communicate a word to the rest of their team, describing it in terms of a secret "keyword" which only that team knows. A second team eavesdrops on the conversation, trying to work out what they're talking about.
With four or more players, divide the players into two teams. (For three players, see the Variations section at the end.)
To generate the random words you'll need one of the following:-
Pick a team to start. Teams then take turns with the following seven steps:-
The team nominates one of its members to be the clue-giver for that turn.
The clue-giver calls a number from 1 to 5, then draws a word card. The word on that card in that number's position is the Keyword for this round. The clue-giver silently shows their entire team the card, so that they all know the word. The other team don't get to see it. The card is then discarded, face-down.
The clue-giver draws a second card and looks at the five words on it, and keeps this card in their hand. They do not show this card to their team.
The clue-giver chooses one of the words on the Target card and attempts to describe it in a way that will allow their team to guess it, while the rival team listening in won't. They do this by talking in terms of the Keyword, which the other team don't know. For example, the clue-giver could start by saying "The Target is the same shape and colour as the Keyword, but smaller, and without the part you lift it up by."
The team can ask questions and chat back and forth as much as they wish, either requesting clarification of the clues or asking general questions about the Target.
The clue-giver may also switch to a different word on the card at any time, if they feel that the one they picked isn't working out. (If you switch to a different Target you can call it "the second Target", to keep the two distinct in your team's imagination.)
Remember that the other team can hear all of this! The clue-giver and their team should avoid being too obvious in what they say, and should keep in mind their big advantage: that the other team don't know what the Keyword is.
The randomly-chosen Keyword is SPIDER. The clue-giver draws a second card, considers its five words and decides to start by clueing WASHING MACHINE as the Target. The team cannot see this second card at all.
In practice, this conversation might go on for some time: the team may realise they've been talking at cross purposes, or decide they want to narrow things down further before proceeding to the guesses.
When the clue-giver's team are confident that they know one of the Target words on the card, and don't want to risk asking any more questions, move to the next step.
The other team now gets to make one guess about any of the Target words, based on what they've heard. If the clue-giver attempted multiple Targets during the conversation, the rival team can choose which one to guess. If they're correct, the clue-giver confirms this and the rival team win 2 points.
A guess is considered to be correct if it's the exact word on the card, or a close synonym for it (if the word is "boulder" and a team guesses "a rock", that's fine).
If the rival team didn't get it, the clue-giver's team now get one guess at any of the Target words that were being clued. If they're correct, or they give a close enough synonym, the clue-giver confirms it and the team win 1 point. Otherwise, nobody scores this round.
The other team now takes a turn. Continue playing until a team reaches 5 points: that team wins!
Have the clue-giver choose a word at random from the second card (in the same manner as the first). The clue-giver must clue that word, and cannot switch to another.
Instead of playing as two teams, give the deck to a random player – they are the clue-giver, and start by picking any other player to give clues to. The game plays with them as a two-person team, under the basic rules, the third player attempting to guess without knowing the Keyword.
First player to 5 points wins (if two players reach 5 at the same time, continue playing to 6 points, etc).
As for three players, except that there's also a Receiver token and a First Guesser token that move around the table. Start the game by giving the deck to one player, the Receiver token to another, and the First Guesser token to a third.
The player with the deck becomes the clue-giver, clueing to the player with the Receiver token. When their conversation is over, the First Guesser gets to make the first guess, followed by the other non-Receiver players in a clockwise order, then finally the Receiver.
When the round ends, pass the deck to the player who guessed, then pass the First Guesser token to the right (skipping the player who has the deck) and the Receiver token to the left (skipping the First Guesser and the player with the deck).
Instead of playing first to five wins, play first to three.
This is probably one of those games where you can ignore the scoring and just play it for fun, isn't it? Two or more players volunteer to be clue-giver and receivers, while the remainder are the eavesdroppers. Swap roles however you like after each round.
At a stretch, you can also play this two-player, non-competitively. Just imagine that your conversation is being overheard by a third party who will pounce on any giveaway statements.
Played in real-time on Slack or Discord or somewhere, the clue-giver just sends the Keyword to their teammates via a private message.
Played asynchronously over Slack, Discord, Twitter, a mailing list, or anything, you can use the casual or 4+ teamless methods described above: two players share a Keyword and have a somewhat real-time conversation where one clues the Target to the other. The remaining players then have as long as they wish to pore over the log of that conversation and deduce what the Target might be - either making undiscussed guesses in sequence or (if you're not playing to keep score) comparing notes and working as a team, getting one guess each before the Receiver makes their guess.
Use the Random Noun Server to generate cards.