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GameDuell Fairness Guarantee
The GameDuell fairness guarantee
  • Equal starting conditions. Both players get the same sets, cards or levels.
  • Fair matching. You can only play against opponents that have a similar skill-level.
  • Free selection of opponents. It's you who chooses whom you want to play with.
Read more about Fair-play at GameDuell

Game rules Zoo 21


Zoo 21 is a combination card game. The aim of the game is to sort the cards from the pack into groups of 21.

The playing screen

  • The pack of cards consists of 52 cards and 2 jokers.
  • There are 4 columns in which cards can be placed.
  • If you can't or don't want to place a card in one of the 4 columns, you have the option to click the discard button which allows you to feed the crocodile 10 cards per level.
Zoo 21 Game board

The aim of the game

  • Sort all the cards from the pack, forming as many groups of 21 as possible.
  • Once you have sorted all 54 cards, you will reach the 2nd level. After the 2nd level, you will enter the bonus level!
  • The more combinations of 21 that you form, the more points you receive.
  • You collect food for the zoo animals with each combination of 21. For each animal that you feed, you receive extra points.

Game controls

  • In order to play the card from the top of the pack, click on the column where you would like to play it.
  • If you have created a group of 21 in a column, the cards disappear and you receive points.
  • You are not allowed to exceed the amount of 21 in any column. If you exceed the amount of 21, you will receive minus points.
  • If you cannot place a card in one of the four columns, click on the discard button in order to feed this card to the crocodile. Be careful though: only a total of 10 cards can be discarded! If you cannot play any more cards, the game is over.
  • If you have successfully cleared the pack, a new level with a new pack of cards will start. After level 2, you will reach the bonus level!
  • The game is over if you cannot play any more cards or the time has run out.

Card values

  • The jack, queen and king are all worth 10 points. The ace is worth either 1 or 11 points. You can therefore complete a group with a sum of 10 or 20 with an ace.
  • By using the joker, you can complete whichever column you wish.
  • If you place 5 cards in a column without exceeding 21, this also counts as a valid combination ("Five Card Charlie").
  • If you can form 21 with three sevens, you receive triple the amount of points!

Feeding bonus

  • Food for an animal appears above each column in which you form a group of 21.
  • Once you have collected food for the animal above all 4 columns, the animal receives the food and you receive 3000 extra points.
  • The next animal which wants to be fed will then appear. Whoever manages to feed all four animals will receive an amusing surprise.

Time and points

  • Time: You have a total of five minutes.
  • Points:
    • Each card placed in a column scores 10 points.
    • Each cleared group of 21 scores 1500 points.
  • Points for series: Provided you don't feed any cards to the crocodile, you form a so-called "series". The more series you form, the more additional series points you receive: for the 2nd group of 21 you receive 100 extra points, for the 3rd, 200 points, for the 4th, 300 points, for the 5th, 400 points etc.
  • Five Card Charlie: If you place 5 cards with a combined sum of less than 21 in a column, you receive 500 extra points.
  • 7-7-7: If you form a group of 21 consisting of three sevens, the points for this group are tripled.
  • Feeding bonus: You receive points for each animal you feed: 3000, 4000, 5000, 6000 etc.
  • Bonus points for remaining time: If you complete both levels, you receive 30 points for each remaining second.
  • Minus points: If you exceed the amount of 21 in any given column, 500 points are taken off your score.
  • Discarding bonus: For each card which you don't feed to the crocodile, you will receive a reward of 500 points at the end of the level.

Bonus level

  • If you complete both levels, the gate to the zoo opens. Here you have to find the pairs of animals which are hiding.
  • Each pair of animals you find scores additional extra points.

Tips and Strategies

  • Try to form groups of 11 as there are a lot of cards worth 10 in the game.
  • Avoid forming too many columns with a sum of 20 as these can only be completed with an ace or joker.
  • Try to form groups of differing amounts in each column. This means you have a better chance of finding a compatible card.
  • Try to spread the groups of 21 across the 4 columns as much as possible. By doing this you receive a greater feeding bonus.