Properly used, Defile is the strongest board clear in all of Hearthstone. Dragon's Fury caps out at 10 points of damage, and while Reckless Flurry can go as high as the sky, it cannot deal with Deathrattle minions. Defile, on the other hand, can go on forever and wipe out anything with the right setup.

Even university employees comment on how Defile is such a nice math puzzle – at the end of which everything explodes if you do it right.

So, how do you do it right?

One, two, three, or?

The first thing that matters when you Defile things is the availability of Spell Damage.

First, with no additional Spell Damage, you need a straightforward 1-2-3-… curve.

This is the kind of easy Defile board you love to see.

Second, you may have a Bloodmage Thalnos available, which makes the first tick a two and Thalnos dies to it, thus proccing the second tick as well. So, you start up at three and go 3-4-5-… from there.

Finally, you may have a Tainted Zealot on board. If the Zealot was already on board and can attack to get rid of its Divine Shield, it functions the same as Thalnos, but if you played it from hand, it will not die to the first tick, so you’re looking at a 2-4-5-6-… curve.

Time to trade

Any minions you have on the board are your first step in solving the Defile math puzzle. Where can you hit? Can you set the health of the opponent’s minions to a perfect curve? Can you set the health of your own minions to fill any gaps?

Trade Voidwalkers into the Jade Behemoth, and the perfect curve is there!

Setting up the curve from hand

If you’re missing some of the points on the board, you can try to play minions from hand to fix it.

The classic fix is Mistress of Mixtures, which goes extremely well with Tainted Zealot, ensuring a two-health minion on the board to proc the second tick, which in turn kills the Tainted Zealot and procs the third tick as well. With this simple Mistress of Mixtures + Tainted Zealot + Defile combo you have guaranteed at least five points of area-of-effect damage alongside four healing for yourself.

Another minion that can be used for the same purpose is Kobold Librarian. As it has only one Health, it can be used without a Spell Damage minion to ensure at least two ticks of Defile, and it also activates the additional ticks with Tainted Zealot the same as Mistress of Mixtures, although of course dealing two points of damage to you instead of healing for four.

While you usually need that one- or two-health minion in the early game for your Defile, there are also various combos that can be useful slightly later in the game.

Possessed Lackey is obviously a two-health minion, but it is rare to be able to set up a Defile play with it as it costs five mana and you generally want to kill off your Lackeys as fast as possible. However, sometimes a Lackey may survive on the board – even if silenced – and help you get to where you need to be.

Control Warlock can attempt to pull the missing link from the opponent’s hand with Dirty Rat, which is rarely a key piece itself, as a six-health minion is rarely what is needed to set up the curve. Gnomeferatu at three Health may come in handy sometimes and you can also intentionally pick up a low-health minion from Stonehill Defender to help set up the perfect curve.

Cubelock, on the other hand, can pull off some really nice things with Prince Taldaram. Because Taldaram is always a 3/3, it can be the missing link at that health point, and you can also use it to copy a Charge minion to get an attack in to reach the desired health curve.

Damage spells to the rescue

Warlock has an impressive assortment of damage spells that can support Defile. Combined with Spell Damage minions, there are lots of variations available: you can use a Mortal Coil to deal one or two points of damage, for example, depending on what exactly you need.

The most straightforward one is Lesser Amethyst Spellstone: just deal a bit of damage. The only real consideration with Spellstone is whether to buff it before casting or not when setting up a Defile. Sometimes you may want to play Kobold Librarian after the Spellstone in order to set up the right health curve on the board, but usually such intricacies are not required, just keep in mind whether your Spellstones are buffed to deal three, five, or seven damage.

Remember the Voidwalker trade? Sometimes it pays off to be greedy and not take the first Defile board you can, you just may get to a position like this, where Spellstone and Defile clear up even more.

Mortal Coil is another fairly simple one. With Mortal Coil, it is important to resist the urge to always use it to draw: it is fine to use it after Defile to draw from the final minion, but if you need to reach some mid-curve health point, do not hesitate to play Mortal Coil before Defile even though you get no card draw from it.

Hellfire is sometimes useful before Defile and sometimes after: If there are low-health minions on the board together with some bigger minions, an early Defile can bring the big ones down to within Hellfire reach. On the other hand, if there are big minions on the board, Hellfire can soften them up for a Defile clear.

Hit with Mistress of Mixtures and then Defile into Hellfire for a full clear.

Two copies of Defile can sometimes also go one after another, often in combination with a Spell Damage minion. It is a less common combination to use though.

A late-game Defile puzzle

Here’s an example of what a fairly typical late-game Defile puzzle looks like. Things are sometimes more complicated with Deathrattle minions, but Warlock is still facing a rather impressive board from a Rogue even with no Deathrattles around.

In a position like this, you want to maximize your board presence and the value you get from your cards so that you will have enough resources to deal with potential upcoming boards as well.
Kobold Librarian gives that crucial one-health minion to get a Defile chain started (Alternatively, one Voidwalker could attack into the Flame Elemental). Hero Powering Edwin VanCleef drops it down to four Health, filling in a gap in the curve. Running a pair of Voidwalkers into Cobalt Scalebane drops it down to five Health, reducing the overall damage a little, so that the Voidlord that is about to come out from Possessed Lackey will retain more of its health.

Moments before Defile is played, the board looks like this.

When Defile does its job right, the end result is predictable.

Have you solved any fun Defile puzzles?

What about you? Have you solved any fun Defile puzzles lately? Let me know all about them!