 <p>You probably want to just use Attributes to specify your validation rules. This is the namespace where all the basic validations exist: <a href="http://msdn.microsoft.com/en-us/library/system.componentmodel.dataannotations.aspx" rel="nofollow">ComonpentModel.DataAnnotations</a>. If you want to get fancier, this NuGet package gives you lots of extra attributes: <a href="http://dataannotationsextensions.org/" rel="nofollow">Data Annotation Extensions</a>. Both of these support client side validation with ASP.NET's MVC unobtrusive validation.</p>