The mechanical Defect has an interesting deck of cards that makes it one of the more intriguing classes to play as inSlay The Spire. It differs dramatically from the Ironclad and Silent in that it plays the long game; building strength and power over time to shred enemies in the later stages of combat rather than fight opportunistically.
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This often means ignoring cheap shots and sticking to a carefully laid out plan no matter what, but for those who can embrace this style and remain patient they can becomemasterful fightersin the late game. If players are looking to develop a long term strategy for the Defect build, here are the strongest cards to consider using.
Updatedon June 16, 2025 by Ben Baker:The key to a deck-building game like Slay The Spire is for players to use their limited resources to maximize results with each turn. Knowing which cards to prioritize can go a long way towards improving overall success. It seemed appropriate to include a few more cards that should also be worth considering. They may not be stronger than the previous ten, but they are definitely worth paying attention to. Here are a few more of the best cards for Defect players, what they do, and a few tips for when to use them.
15Chill
Chill is a great card for opening up combat. At zero cost it Channels a Frost orb for every enemy in combat and then Exhausts afterward. It’s not exactly a game-changer, but it does act to give the player a solid footing while stalling for better cards.
After all, the Defect character is about stalling long enough to snowball to absurd levels and obliterate opponents. Chill when used early on can achieve that. Even later in the game, it acts as a one-turn delay to bide time for something better.
14Coolheaded
Coolheaded costs one energy and will Channel one Frost and allow the player to draw one card. Coolheaded serves as more of a synergy card with things like Capacitor or Consume. But on its own, it still serves a valuable role.
It serves to give the player some Frost and hopefully a more useful card through the draw. Later in the game, it loses some steam and really needs synergy for it to be useful. In the beginning, it’s a solid card that can give the player some options.
13Reinforced Body
Reinforced Body has an X cost and will provide seven Block X number of times. Like all X cards the X is dependent on the energy consumed and with this card, the more energy the better. Having seven Block for one turn is great, but getting it for two or even three times is phenomenal.
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It doesn’t rank higher because its usefulness is dependent on the energy available and it consumes everything at once. Still, seven Block regardless of how long it lasts is nothing to be upset about. Combine this with Chemical X or Recycle and the player is a force to be reckoned with.
12Steam Barrier
Steam Barrier has no cost and provides six Block with the caveat of decreasing the card’s Block by one each time it’s used. Six Block for zero cost is incredible for Defect and a great way to get some defenses up to build power.
That decrease in Block is why the card doesn’t rank higher. It essentially has six uses before it becomes useless and each use it sees a diminish in helpfulness. Granted, most players won’t ever use it that many times, but there is a cap on the card’s power in a long battle.
11Electrodynamics
Electrodynamics costs two energy and causes Lightning attacks to strike all enemies. It also Channels two Lightning when used. The one-two punch of enhancing Lightning attacks and then providing Lightning is what makes this card so powerful.
It’s also a strong component for Defect’s scaling-over-time style of play. All Lightning attacks will now become AOE attacks without losing their potency. Hallway battles become a breeze after utilizing this card and it synergizes very well with Static Discharge.
10Glacier
Glacier is a skill card that gives nine block and channels two frost orbs. The nine block is handy for negating solid damage in an upcoming attack and the channeling effect will load two frost orbs to give improved defensive capabilities.
Frost orbs struggle in the beginning, but if the player can hold out they create an impenetrable wall of defense that make combat a matter of attrition. It’s a strong card, but you definitely need the right setup to take advantage of the frost orb channeling.
9Streamline
This attack card is the epitome of the Defect’s overall strategy. Initially it costs two energy to deal 15 damage and enters the discard pile, but every time it’s used afterward, be it through reshuffling or drawing from the discard, it’s cost goes down by one until it hits zero for the remainder of combat.
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This means after a total of three uses players will have an attack card that does 15 damage and costs zero energy. This is unbelievably helpful as it allows players to allocate that energy to other cards while still doing hefty damage.
8Hologram
The Hologram card is an example of why cards like Streamline are so useful. Hologram gives a nice three block and then allows the player to take a card from the discard pile and put it in their hand. With the low energy cost of one players can easily use many other cards in the deck after playing this card.
Granted it does exhaust after a single use, but it potentially lets the player reuse very powerful cards to hit the enemy twice in one turn or ratchet block up to incredible heights prior to a major attack.
7Static Discharge
This passive power card is helpful for whittling down opponents while the player is busy building up the character’s overall abilities. Every time Defect takes damage with this card in play it will channel one lightning.
Lightning are orbs meant for damage dealt over time with each turn. Having the ability to channel Lightning every time Defect takes damage can quickly build up lightning abilities and whittle down opponents.
6Machine Learning
This power is much more straightforward and arguably more useful for both short term combat and long-term power up. Every turn after drawing five cards the player can draw an additional sixth card. Considering how many zero cost cards there are in a Defect deck, odds are the player will be able to use whatever they draw without worrying about the energy cost.
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This power gives yet another chance to deal damage, set orbs, or build block reserves. Six cards in a zero cost deck can go a long, long way.
