My main is energy and today I can buy my 3rd Thea for 1000 in the store but I wonder if you ever want 3 uniques in a deck, and of course which ones you want 3 of?

Now tell me everything!

That entirely depend on how you chose to play your deck. I will try and give a few example to help you out.

First let us look at an undead deacy deck. Similar to Irva's Undead (linked below). In this deck, Irva is very important. You could chose to run 3 Irva's, but over a long time, you will likely find, already having an irva on the board, you have dead cards cycling through your deck. Choosing to have 2 I find, is acceptable because she will always be at the back of a row, and not in danger. She is out of burn range. Overall she should be safe.

If you compare her (irva) to Reloras in a tempo order deck. They are similar, but, Reloras will often be played in a middle row to take advantage of his Resonance ability. He is in alot more danger, do to primarily being on the middle row. I find it is often better to run 3 Reloras (depending on how much your deck depends on him) because he will die often, and needs to be played several times in a game.

My third example is a Mid game growth deck. Mostly middle cost creatures, but also runs god hand and Jarl Urhald. While Jarl is a powerful creature, I am nearing the end of my curve. I want to end the game as quickly as possible. If my Jarl Urhald dies, likely my game is over. I makes more since to run more God Hands then 2 Jarls, because, I will (almost) never play Jarl twice in one game, as when Jarl is played I need to win the game quickly to survive. Therefor it would be illogical to run 2 Jarls, if i will only ever play one.

Now in answer to your question. As said before, It all depends on your play style. If you run 2 theas, and protect them as much as possible when in play, then you should be good. However If you like running Thea at the front of your row, and using her as a wall, she is likely to die, and you may want to have 3 in your deck. However this only works If you have a late stalling curve, and Win late late game, you could consider 3 theas. Just be careful not to *Unique kill, and good luck! Just keep experimenting and see what works for you.

(decay deck - {"deck":"","author":"Ikraen","types":[163,163,164,164,349,349,349,179,179,268,268,181,181,265,265,350,350,350,183,183,172,195,195,195,362,362,177,177,353,353,271,271,200,200,352,352,382,59,59,194,194,343,381,352,271,382,268,164,194,381]} )

Thanks just what I am looking for.

For Thea specifically she is not as important to the deck as Irva or Reloras I think, she is more just a really powerful creature in her own right. Also she can be protected by stuff like potion of resistance and pretty tough units like Ironclads, Cannon Automatons and structures. I guess more than 2 Theas might be pushing it.

At least I think I will put off buying the 3rd one for some time unless someone urges me to get her.

Edit: One deck I am wondering about is the one that casts Skull Shrine to play big energy minions very early, maybe having 3 Theas is important there to have a bigger chance of getting her early.

Again for that deck, While Thea is great to get out early, often only 2 are run. If you can get a thea out early that is great, but you don't want dead cards in your hand, which is all a unique is if you have one on the board. Expecially after the set 7 release, 3 thea's Will hardly ever be run, especially in competitive decks, once there are more high cost energy creatures.

I am generally 1600 rating player and I mostly use Ramping Energy and MER in ranked and tournament play. For Ramping Energy (the one you're thinking of) I run 3x Thea. In this deck you can easily get a Thea out round 10 (or your 5th turn) in comparison let's say Growth which only gets a Great Wolf by this time. However the reason for 3x Thea is because on average you Thea won't get more than 1 turn to attack, even with potion of resistance. This is because against Order it almost always gets pushed back, against Decay it almost always gets damning cursed and against Growth you almost never want to play it. It dies pretty fast against Energy as well. However back to back Thea is really difficult for your opponent to deal with and having 3 of them never harmed me once. I highly recommend running 3 of them in the Big Bad Energy decks. However I am sure someone like Donkey who created this deck might be able to give a better opinion on this matter.

Fair Enough. I am undoubtedly not primarily an energy player, and so I really appreciate the different opinion tak4n, And maybe 3 thea's does work, but i feel, at a lower level, and for a lower level player (not top 100, no offence meant) A similar deck can be effectively with only 2 thea's, and that his resources can be used elsewhere for now. Still interested in this discussion. What do you think?

Discussion of quantity of unique creatures has always been an interesting one. The first factor is definitely quality some unique's are simply more powerful in certain decks. The second factor is how long you expect the creature to survive. The third would be card flow the idea being the faster you can cycle through your deck the less necessary running a higher amount of unique's becomes this is shown largely with uhu who's power level warrants three, but due to its tendency to live and snargl omelette speeding through gravelocks it is often run at two.
The forth correlates with with the first and that is impact on the turn it is played. Typically the unique's with the most impact the turn they are summoned are Jarl Urhald, Reloras, and Irva. Of these three jarl is typically ran at two as he costs so much and tends to survive while Reloras and Irva are so valuable during most stages of the game they can be much more easily ran at three (I still prefer 2 in nearly all cases.) These were the four simplest reasons for running a certain number of unique's I could come up with hope i helped

I think you should go with two unique for every unique card except Reloras because he's just too good.

Irva also means Harvesters. While it doesn't happen every game I have had one or two where I've played Irva causing my existing Irva to die which activated my Harvester and my new Irva as a bonus was in a better position to machine gun shots as my undead attacked. Combined with her lower cost in general she's a unique that it's safe to play more of. But yeah, you don't want three of Urhald or Thea. Too expensive. Reloras has a bad habit of dying as well which combined with how important he is means that you'll sometimes play three of him. But other than those two I don't see any reason to play more than two of a unique and sometimes only one to fill out that last slot(if they're useful but not vital for your play...Thea, I'm looking at you).

While Jarl is a powerful creature, I am nearing the end of my curve. I want to end the game as quickly as possible. If my Jarl Urhald dies, likely my game is over. I makes more since to run more God Hands then 2 Jarls, because, I will (almost) never play Jarl twice in one game, as when Jarl is played I need to win the game quickly to survive.