Identify the incorrect number in the following series:
12, 10, 6, 1, -8, -18

Let's analyze the differences between consecutive terms:
$$10-12=-2$$

$$6-10=-4$$

Following the pattern of consecutive even numbers subtracted ($-2,-4,-6,-8,-10$):
The next term should be:

$$6-6=0$$

If the term is 0:

$$0-8=-8$$

$$-8-10=-18$$

This perfectly matches the rest of the series. Therefore, 1 is incorrect and should be replaced by 0.