# How much value does hero damage add?

It is often said that a card got "value" when it can trade favorably, e.g. 2-for-1. But how much value does damage done to the hero add to the equation? For example, if a minion hits the hero once and then trades 1-for-1?

When the same minion dies in an AoE spell, how much damage should it have done to "be worth it"? (As opposed to a minion who dies to an AoE spell without having done anything)

There is a great article series explaining the resource system of Hearthstone. In the context of your question, this is what can be learned from it:

Unlike, say, Yu-Gi-Oh!, where card advantage is extremely important and pretty much all that matters, it has a much less prominent role in Hearthstone, where the other resources (tempo and hero life) are a lot more important. The classical "1-for-1" or "2-for-1" terms only account for card advantage, which is a generally good measure of a move's value in games where card advantage is highly relevant. But in Hearthstone, other factors are very important and simply comparing the number of cards involved doesn't cut it.

Now bringing in hero life, a third resource enters the equation, and in Hearthstone, this is an important one because only Taunt can stop the opponent from just hammering it down (staying with Yu-Gi-Oh! as a comparison, any Monster will stop the opponent from attacking your life points there, so they are far less vulnerable and thus have less value in relation to card advantage). What you get is a 3-element vector of resource effect. The example above would result in a `[0 +3 0]` vs. a `[0 -4 0]`, while the case you mentioned, assuming a minion with 4 attack and the opponent using a card of equal mana cost to trade, would result in a `[0 0 0]` vs. a `[0 0 +4]`. That is, assuming your opponent does trade equally. In reality, you trading vs. your opponent trading will generally result in a tempo difference because the player initiating the trade is the one who can choose how to do it and thus maximize his own tempo advantage. So if you have a 3-mana 4/3 minion and choose to attack the hero for `[0 0 +4]` instead of destroying a 4-mana 5/4 minion for `[0 +1 0]`, the opponent might be able to use a 2-mana spell to trade off your minion, resulting in a total move effect of `[0 -1 +4]` as opposed to `[0 +3 -3]` if the opponent used the spell to damage your hero instead. However, since this will leave the 5/4 minion on the opponent's field and could leave your field wide open, this might turn out to end as a `[0 -1 -1]` move instead.

At that point, deciding which move to make become a judgment call based on the total situation, notably the absolute values of each resource. If your opponent is sitting at a total of 7 cards on field and in hand combined, cards with total mana cost of 9 on field and 23 hero life remaining, his resource total is `[7 9 23]`. This is a situation where you will generally (!) want to see tempo as highest priority. The reason is that card advantage is usually gained in +/-1 increments, sometimes not even that, while tempo is more easily gained in larger chunks. Hero life, on the other hand, nearly always comes as a trade-off and gaining a life advantage usually means taking a card advantage and/or tempo loss. Unless we're talking about a 10 life Pyroblast, going for hero life is probably a bad call with those totals. If your opponent sits at `[2 6 19]`, card advantage becomes a major target because you might be able to bring your opponent down to `[0 0 x]` while still having cards left yourself. This is always a good thing because they will have to play off their one card per turn, which is luck based and sometimes called top-deck mode. Putting your opponent there is only second to actually winning the game directly or setting up a secure win for the next turn. If you can go for it, it's usually the best option. But if their total is `[5 10 10]`, life becomes important, especially if you're ahead in life and behind in the rest. Going for hero life in this situation could win you the game before their card and tempo advantage can overwhelm you. It really comes down to their weakest point at a specific time.

To summarize, you can't just look at card advantage alone. All 3 resources are comparably important in Hearthstone, so you should evaluate each move's value with respect to each of the 3 resources, for example by denoting value as a 3-element vector. Which move has the highest net value depends on

• the move's value vector
• the total resource advantage vector (differences between you and the opponent)
• the opponent's absolute resources vector