NUnit

If you are using NUnit, then you need to provide the attributes that it needs to discover and run your specifications. The good news is that you only have to provide this information once, on your base class - all of the specifications that you write will inherit from this class and not need any attributes.

Text

[TestFixture]
public abstract class ScenarioFor<TSut, TStory> : Specify.ScenarioFor<TSut, TStory>
    where TSut : class
    where TStory : Story, new()
{
    [Test]
    public override void Specify()
    {
        base.Specify();
    }
}

[TestFixture]
public abstract class ScenarioFor<TSut> : Specify.ScenarioFor<TSut> 
    where TSut : class
{
    [Test]
    public override void Specify()
    {
        base.Specify();
    }
}