Amie Albrecht recently posted a most wonderful blog post about SET, and it reminded me there were some SET-related things I should post too.

The first is this little reflection on how I go about teaching people to play SET. Amie talks here about a very excellent way to do this, which is to get people to look at the whole deck of cards and organise them all to see if they can be sure they have them all, then notice the patterns there. But what do you do if you’re partway through a game in a public place and someone comes over to ask what you’re doing? Well, this is how I go about explaining it in that situation…

Imagine we have a game of SET going on the table, which means there are twelve cards laid out face up on the table and a group of people looking at them.

(You may notice these are not the same as the usual SET cards. For a start, they are much bigger, and secondly the colours are different. The size is because I wanted cards you could see from a long way away. The colours are because the original cards are red, green and purple, which are not good for colourblind people, so I chose primary colours in different tones. Also I have the attributes written on each card. If you want my versions of the SET cards for printing, you can find them here.)

Someone walks over and asks what we’re doing. I say, “We’re playing a game called SET, would you like to join in?” They say, “But I don’t know how to play.” And I reply, “I can teach you. Have a look at the cards and tell me what you notice.”

People almost always notice that there are several shapes or colours, and very rarely mention the patterns or number of shapes. Some people notice that there are twelve cards in rows. Whatever people notice, I ask them if they notice anything else before moving forward, and within the first couple of things they say, they always mention some attribute the cards have. Then I will say something like, “You said you noticed different colours. How many colours do you see?” I’ll do this for each attribute they have noticed, and they will notice three types of each.

Then I’ll ask them what else they notice, but I’ll be more specific this time. I’ll say, “You noticed that there were different shapes and colours. What else makes cards different from each other?” At this point they’ll start to notice the patterns and number of shapes. (I find it very interesting that people usually don’t talk about these until you specifically mention comparing cards to each other. The number of symbols per card in particular is very rare for people to mention without explicit prompting.) And I’ll ask them how many options there are for those too.

Now I sum up where we are up to: “So you’ve noticed there are three different colours, three different shapes, three different patterns, and three different numbers. That’s important to how the game works, and actually every combination of those is somewhere in the deck of cards.”

Now we are ready to move on to how the game works. I will pick up two cards and ask them to compare the cards. That is, I’ll ask what’s similar and what’s different about the cards. They’ll tell me, for example, that they’re both blue, they both have two, they’re different colours, and different patterns.

Now I ask, “If you had to pick a third card to go with these two, what would you pick? It may or may not be on the table — just describe what the card would be.” People invariably always pick the right card to complete the set. I ask them why they chose that card and they’ll say something like, “Well those two were both blue, so I thought I should choose blue, but they were different shading, so I chose the missing shading we didn’t have yet.”

At which point I say, “That’s exactly what a SET is. When you pick two, the third one has to match the things that match or be the third option for the things that are different.” We try it with some other pairs with different levels of similarity and difference so that they can get the idea.

And only now do I explain how the game works. I explain how we will all stare at the twelve cards, and call out SET when we see one, and whoever sees it first will claim it. Then I invite them to join in.

While the rest of us play, I always make sure that anyone who claims a SET explains why it is a SET to the group, for the benefit of the newcomers. We also explain why things that aren’t SETs aren’t. This helps to solidify the rules as the game progresses.

Note the usual rule of a SET where each attribute in turn is either all same or all different doesn’t seem to work so well for on-the-fly teaching, whereas the rule I said earlier that “the third card has to match the things that match and be the third option for things that are different” seems to make a lot more sense to people. The traditional rule does tend to emerge naturally as the game progresses, interestingly.

The reason I go through this process is that just trying to explain what a SET is to people almost never works. This method always ends up with people constructing for themselves how a SET must be, without me having to explain it. If I tell them about the attributes and tell them the rule for being a SET, they always have to keep clarifying over and over. This method is based on their own noticing and reasoning and so it just sticks better sooner.

Let me summarise my method again:

1. Ask people what they notice until they mention at least one attribute of the cards like colour or shape.
2. Ask how many options there are for those attributes.
3. Ask what else makes the cards similar or different, so that the other attributes appear.
4. Ask how many options there are for those attributes.
5. Summarise the options for the four attributes and tell them that every combination appears in the deck.
6. Pick two cards and ask what the third card might be that completes the set.
7. Ask why they chose that card, and confirm that yes this is how a SET is made. “If something matches the third card has to match too, if something is different, the third card has to have the third option.”
8. Explain how to claim a SET.
9. Make sure players explain why things are or are not SETs as the game is played.

There you go. I hope this is useful to you for those times when you need to explain SET on the fly. It happens to me a lot, but then I deliberately put myself in such situations by bringing this game out at One Hundred Factorial or at games nights or orientation activities!