Understanding Fel Reaver: Hearthstone Theory


Last week, I spent most of my streaming time playing versions of the MechaMage deck that I detailed in my last post. One of the cards that I was experimenting with for a while was Fel Reaver, which generated a remarkably aggressive response from Twitch chat. While vitriolic responses are Twitch chat’s standard operating procedure, in this case I felt compelled to educate rather than ignore, because the negativity directed toward Fel Reaver seemed to be the result of simply misunderstanding the nature of the card and its drawback. I want to discuss a bit of Hearthstone theory and how it relates to Fel Reaver.

So let’s start at the beginning.

millstoneYou might have heard the term “Milling” thrown around in Hearthstone to describe effects or strategies that aim to win by depleting an opponent’s deck. The origin of the term comes from the Magic card Millstone, which was released in the Antiquities expansion in March of 1994 – incidentally, about a month after I started playing. In Magic, if a player has to draw a card from an empty deck, that player loses the game.

Millstone was a much beloved card during Magic’s early days. Some of the most popular strategies of early competitive Magic involved neutralizing all of the opponent’s creatures with counterspells and removal effects and slowly depleting their deck with Millstone. In fact, the very first Magic Pro Tour back in 1995 was won by Mike Loconto playing a Blue/White deck built around Millstone.

In addition to being among the most popular cards in the game, Millstone was also one of the most frequently misunderstood. One of the earliest advances in Magic theory was the idea of “Card Advantage”, which was a term used to describe the advantage gained when a player was able to draw extra cards, or to neutralize multiple opposing cards with one of their own.

Some players referred to each activation of Millstone as generating card advantage. Their argument was that using the Millstone meant that those cards were now gone and they would not have to face them later in the game. That understanding of card advantage is flawed, however, because card advantage only applies to resources that are actually available for a player to use.

Cards that have not yet been drawn aren’t a resource in the same way as cards in hand. Playing Mind Twist and forcing your opponent to discard five cards generates card advantage, because your opponent now has five fewer cards they can choose to play. Playing Mind Sculpt, on the other hand, forces your opponent to put their top seven cards from their deck into their discard pile. This does not generate card advantage, because the opponent still has the same number of cards in their hand to work with.

Millstone and cards like it are generally examples of card disadvantage, because they do not intrinsically impact the game state. In fact, in every game in which Millstone does not outright win the game by running the opponent out of cards, it effectively has zero impact.

200px-Fel_ReaverThe same is true of Fel Reaver’s drawback. In most aggressive decks where Fel Reaver sees play, its drawback has essentially no impact at all. Except in a game that a player loses due to running out of cards that they would have otherwise won, Fel Reaver’s drawback might as well not exist.

This is a concept that is difficult for some players to accept. When I was playing with Fel Reaver on my stream and my opponent played a bunch of cards and burned my Fireballs and Antonitas, Twitch chat was always in an uproar about how bad Fel Reaver was because I “lost” those cards.

The reality, however, is that the order of cards in your deck at any point is random, and Fel Reaver is just as likely to burn your worst cards as your best. In fact, for every time that Fel Reaver burns a game winning Fireball from the top of your deck, it will also burn three cards that are on top of that same Fireball to let you draw it in time.

Think of it as Schrodinger’s Fireball. At any time, it’s both on the top and the bottom of your deck, and you can’t know until you draw it.

There is one real consideration with Fel Reaver to keep in mind, though, and that’s the information exposed by the burned cards. The fact that your opponent sees the cards lost to Fel Reaver means that they know that you can no longer draw them.

This is a more important factor in Hearthstone than it is in Magic, because the two-of limit for cards and one-of limit for Legendaries (compared to four copies in Magic) means that you can more easily eliminate the need to play around particular cards.

If, for instance, you burn both of your Fireballs, or your Antonitas, your opponent knows that they don’t have to worry about them and they can adjust their plays accordingly. Most of the time, this informational advantage is going to be a minor one, but sometimes knowing that you can take a particular line of play because your opponent can’t possibly have a card that can punish you can make the difference between winning and losing.

Now, this isn’t to say that Fel Reaver doesn’t have a very real drawback that comes up sometimes. There are certainly games that you’ll lose to fatigue because of cards burned by Fel Reaver. But it’s important to recognize that outside of those games, and the minor informational edge it can offer your opponent, Fel Reaver’s drawback is not actually impacting your ability to win. While I was playing with it, I lost far more games to Fel Reaver’s real hidden drawback than the one printed on the card – the fact that it dies to Big Game Hunter.

For reference, here’s the list I was playing.


While I actually ultimately decided to cut Fel Reaver from the deck, it was more due to the “hidden” drawback of Big Game Hunter than the actual text on the card. More recently, I’ve been trying Sludge Belchers due to the popularity of other aggressive decks on ladder, though I also like Strifecro’s idea of playing Azure Drakes to help refill your hand that he used to win the Kinguin Charity Tournament with a 4-0 sweep using MechMage in the finals.


If you want to see me playing this and other decks, as well as defending Fel Reaver against its detractors, be sure to tune in to my stream. I stream almost every weekday morning at 10 AM PST, as well as some evenings and weekends. I hope to see you there!


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