A deck in Artifact is the most important thing you choose before entering a match. It defines your playstyle, strengths and weaknesses, tactics and strategy. Building a balanced deck is one of the keys to victory.
Any deck should have:
It is not confirmed yet but it looks like there will be no limitation about colors in a deck. The below list is based on the initial assumption from Mar 2018 that there is a limitation of 2 colors per deck. This assumption seems to be incorrect as of May 2018 see this RPS article
Since there are 4 different card colors, there are 6 possible types of decks: