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How many tokens were infected?

Stuck inside with nothing to do? Grab a chess board and see if you can control an outbreak in this isolation game!

Materials

• A chess board. If you don’t have one, we have a chessboard you can print
• 12 tokens (coins, plastic discs or draughts)
• 12 coloured stickers (optional)

The setup

1. Place a sticker on the back of every token or coin. Alternatively, if you’re using coins, you can also use tails to identify which tokens are ‘infected’.
2. Place a single token on each of the four dark squares along the row nearest to you on the chess board. Make sure each token has the sticker facing down, or its head-side facing up.
3. Turn one of those tokens over to mark it as ‘infected’.
4. Place another four tokens on the dark squares of the third row on the chess board.
5. Place the last four tokens on the dark squares on the fifth row on the chess board.
6. Before we start, keep in mind that all the tokens stay on dark squares – they’re never on the light ones.
7. Tokens always move one space diagonally forwards, either to the left or to the right, and only into empty squares. That means most pieces have two places they can move to, unless they’re on the edge of the board, or there’s a token in the way.

The game

1. Move any two uninfected tokens diagonally forward one space.
2. Move one infected token diagonally forward one space.
3. Turn over any uninfected tokens that are adjacent (on one of the surrounding four dark squares) to any infected token. Be careful! If there’s a big group of counters, the infection can spread to all of them!
4. Repeat steps one to three. Any uninfected tokens that are in the furthest row can be removed from the board during their movement.
5. The round ends when only infected tokens make up the end row or no uninfected tokens remain on the board.
6. Note down how many tokens were infected.
7. Repeat the game to see if you can reduce this number.

What’s happening?

It might take a few tries to work out a strategy, but you’ll soon find one way to protect your uninfected tokens is to ensure there is plenty of space around those that are infected. One infected token can infect as many as three others in one move. Those can then in turn each infect up to another three, which can quickly add up.

Many pathogens, such as the virus that causes COVID-19, spread quite easily through infected droplets in the air we cough and sneeze from our lungs. A good, strong cough by a large adult can reach up to 2 metres away, which is why authorities recommend we keep a distance of at least 1.5 metres from most people.

Better still, we should keep away from as many people as possible during outbreaks. Unlike the tokens in this game, many people don’t have an easy way to tell if they’re infected. Called ‘carriers’, they can still produce infected droplets, but don’t show any symptoms.

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