What is the 21 drinking game?
The 21 drinking game is a counting game: taking turns, each player says one, two or three numbers in a row, and whoever is forced to say 21 loses. You don't need anything, it takes ten seconds to explain and every round is short, so it's perfect for starting the night or squeezing in between two longer games.
Don't mix it up with blackjack (the card game also called 21): there's no deck and no betting here, just counting out loud. And in this drinking version, the event numbers make every round different.
Strategy: the multiples-of-4 trick
There's a math trick to it. Whoever ends their turn on 20 forces the next player to say 21. And since each turn adds 1 to 3, whoever ends on 16 can always reach 20: if the other player adds 1, you add 3; if they add 2, you add 2; if they add 3, you add 1. The same goes for 12, 8 and 4. With two players, whoever goes second can always win by ending on 4, 8, 12, 16 and 20.
With three or more players there's no sure thing, because other people add numbers between your turns. Still, 20 is the key number: if it's your turn when the count is at 17, 18 or 19, get to 20 and 21 goes to the next person. And watch out for the events: landing on 15 lets you hand out sips, but in a two-player game it leaves 16 to your opponent.
21 drinking game rule ideas
The game already comes with built-in rules: at 5 someone makes up a rule for the round and at 20 someone sets one for the next round. If you're stuck for ideas, try these: no saying “seven,” clap instead; say “buzz” instead of any multiple of 3; anyone who looks at their phone takes a sip (or water); only talk in a fake accent; or the person on your left has to say your numbers for you.
Classic house rule: in a lot of college versions, whoever says 21 picks a number and gives it a new rule (swap it for a clap, a word or a gesture) that stays for the rest of the game. The phone doesn't track it, so the group has to remember, and that's half the fun.
No alcohol: whoever says 21 does a dare the group picks or takes a point, and whoever has the fewest points at the end wins. The sips from the events can be swapped for water.
If you'd rather everyone add from their own phone, create a room: you all see the count on your screen and each person taps on their turn, on a video call too. If you like fast games with pressure, also try Word Bomb and Three Man.
When to play the 21 drinking game
It's ideal for warming up a pregame, for groups who don't want to learn long rules and for a break between two longer games: rounds are short and you can stop whenever you want.
It works from 2 people, so it's great for a night in as a couple or with roommates too. With a big group, rounds go faster and you almost never know who's going to get stuck with 21.