If you don't have a rice cooker, you can cook rice in your crock pot. It will cook (steam) the same way that it does in a rice cooker. It will just take a little (okay A Lot) longer, but sometimes that can be a great thing.
Unless your recipe states differently, rice should be added to the crock pot at the end of the cooking time. Rice left to cook in the crock pot for hours tends to become mushy and tasteless. Always add sufficient water or liquid to cook the rice.
Follow the guidelines below.
White converted rice should be added to the crock pot with about 2 hours left of cooking time; add an additional 1 1/2 cups (360 ml) of water or other liquid per 1 cup of rice to the crock pot. Cook on low heat.
Brown rice should be added to the crock pot with 3 hours left of cooking time; add an additional 1 1/2 cups (360 ml) of water or other liquid per 1 cup of rice to the crock pot. Cook on low heat.
Wild rice should be added to the crock pot with 3 hours left of cooking time; add an additional 2 cups (480 ml) of water or other liquid per 1 cup of wild rice to the crock pot. Cook on low heat.