Each tile may, in an upcoming update, have a rarity limitation within the deck (and tile circulation as well) where you are limited to the amount of tiles with that name in your deck. The Digital Vampire is a Rare tile and can only have 2 put in your deck - meaning, you can only have 2 Digital Vampire present in your deck.
Rarity Breakdown:
Common: 4 tiles per deck
Scarce: 3 tiles per deck
Rare: 2 tiles per deck
Legendary: 1 tile per deck
Each tile will have a different colored background. Common - green, Scarce - blue, Rare - red, Legendary - purple.
This is not set in stone but I love how the tiles look and it gives me more room to tinker with tiles.
let me know what you think...