A while back I read somewhere that you should strive for a two to one ratio of low cost to high cost upgrades. So if I had three 3 Cost upgrades I would need at least 6 two cost upgrade. Is this a hard a fast rule in deck building? I have seen some tourney winning decks that may have as many as six 3 cost upgrades in their total of 12. Just wondering about the validity of this 2-1 Ratio idea. Thanks

In no way is this a hard and fast rule. It may be a vague guideline. But certain decks generate significantly more resources than others, and so they can bring more expensive upgrades to the table. But you have to keep in mind other factors. How many of your dice have pay sides? How many of your events cost money? On top of how easily your deck makes money. These will all determine how often you think you will be able to pay for your 3+ cost upgrades. 2:1 two or less cost may be okay, but I know in some of my decks I go for the big upgrades because I know my deck can afford it. Others I go less because I need that money.

In trying to adhere to this rule, I've also noticed a lack of damage output which also made me question the ratio.

My decks currently have around 11 sides with resources and I typically try to make my cost curve proportional in the sense that I have more zero cost cards than one cost, more 1 cost than two cost etc. so what you are saying is that I may have room for more powerful upgrades than I think I do.

If you find yourself with extra resources certainly. But it all is very much case by case. If you find yourself wanting resources as you play you will want to increase your lower cost cards.

If your deck is designed around making resources, you can do the 3 -4 cost upgrades. If your deck barely makes any resources and needs those 2 resources each round for evens, you are looking at 0-1 cost upgrades. You design your resource usage, both upgrades and events, around your decks resource tempo, which there are plenty of cards to increase.

2:1 is a very generic rule for first building decks when learning. It's certainly not a one size fits all. Not that I'm saying that's a bad thing just pointing out that its a rule of thumb that helps you early on to build decks without making them unplayable due to cost curve rather than being a rule for how to build the optimal deck.

Two good examples would be the new five dice villains that is a very strong deck where the most expensive upgrade is one resource. Where as its not uncommon for an aayala padawan padawan deck with reaping the crystal and it binds all things running more three cost upgrades than two costers.