So what are these tiers?

Tier 1:

Every submission begins its life in “Tier 1,” where RHX requires a very limited amount of content so we can assess it faster. From here, we figure out whether or not we are interested and want to see more. This tier is specifically designed so RHX is able to read through more submissions in a shorter amount of time.

Tier 2:

If RHX asks to see more of your project, then you’ve reached "Tier 2." Your acceptance isn’t guaranteed, however, it does mean that we’re quite interested and want an in-depth look into your project. Think of it this way, there's no Tier 3.