Per Wikipedia: A **set** consists of three cards which satisfy all of these conditions:

- They all have the same number, or they have three different numbers.
- They all have the same symbol, or they have three different symbols.
- They all have the same border, or they have three different border.
- They all have the same color, or they have three different colors.

The rules of Set are summarized by: If you can sort a group of three cards into "Two of ____ and one of _____," then it is not a set.

### Valid set:

### Valid set:

### Invalid set: