Preheat oven to 350 degrees. Spray a 9×13 baking dish with non-stick cooking spray.
In a large bowl combine the soup, milk, sour cream, Ro-tel, 1 1/2 cup of cheese and taco seasoning.
Add chicken, and combine.
1st layer- Spread the refried beans in the bottom of the baking dish
2nd layer - 1/3 of the Doritos
3rd layer - 1/2 of the chicken mixture
4th layer - 1/3 of the Doritos
5th layer - 1/2 of the chicken mixture
6th layer - the rest of the cheese
7th layer - the rest of the Doritos
Cover and bake for 30-35 minutes. (Bake the last 5 minutes uncovered)
Serve with whatever toppings your heart desires and enjoy!