Add a new rule “Hat” as follows:

Each monkey has a Hat tracked in the GNDT. The default hat for a new monkey is Blue. The list of hats a monkey can be is known as the hat list. When an action makes a monkey change hat (and does not specify which hat to change to) they change to the hat 1 lower on the list than their current hat (If their hat is at the bottom of the list they change to the first hat).

Add a sub-rule of “Hat” “Hat List” as follows:

The following is the list of hats known as the Hat List:

1. Blue
2. Green
3. Yellow
4. Red

Add a new sub-rule to “Hammers” “Hat” as follows:

If a Hat hammer is used on another monkey, one of the following happens:
If that monkey has a Blue hat, that monkey changes hat.
If that monkey has a Green hat and has less than 10 bananas, increase the number of bananas that monkey has by 3.
If that monkey has a Green hat and has more than 9 bananas, change the hat of that monkey to Red.
If that monkey has a Yellow hat, that monkey moves to the back of the line.
If that monkey has a Red hat and has more than 2 bananas, decrease the number of bananas that monkey has by 3.
If that monkey has a Red hat and has less than 3 bananas, change the hat of that monkey to Green.

Add to the end of “Doing the Dance” :

Name: Hat Change n_A; Complexity 1; The monkey in position n_A changes hat.

Finally, randomly set the hat of all monkeys.