I dropped into the fourth floor with three health and a single Copper Knife. Enemies closed like breath on glass and a single wrong Gem choice would turn that run into a funeral march. I remember the moment I realized one tiny modifier could remake the whole deck.
I’ve played dozens of runs, tested oddball combos on Steam and swapped notes in Discord with streamers. You’ll read the table below, but I’ll also point at the Gems that actually matter for playstyles, and why you should refuse certain shiny offers.
All Gem effects in Vampire Crawlers
Observation: At a busy drafting table you often have three seconds to decide — the wrong click haunts the next ten rooms.
Below is the single reference I wish I’d had during my first 50 runs: every Gem, exactly what it does, and the small, game-changing rules about pairing them with cards and characters. Think of some Gems like a Swiss Army knife for a single card, and others as a compass guiding your deck toward a specific loop or failure.
| Name | Effect |
|---|---|
| Amount | Adds the number of projectiles. |
| Area | Adds the area effect of a card. |
| Armor | Adds Armor. |
| Armor Strike | Deal Armor as damage when played. |
| Bombard | Adds an explosive bomb. |
| Coin Card | Creates Coin Shards. |
| Copy | The card is copied when used. |
| Countdown | Mana cost reduces when not used. |
| Crawler Caller | Summon all Crawlers to Hand. |
| Decimate | Deals 10% of enemy’s health as damage. |
| Destroy | The card gets destroyed, but you get coins in return. |
| Double Damage | Hits twice as hard. |
| Drain | Heals when the card kills an enemy. |
| Draw | Draws an extra card. |
| Duration | Increases Duration stat. |
| Easy Combo | The card always benefits from combo. |
| Echo | Replays the previous card’s effect. |
| Evolution | Evolves the card into a more powerful weapon. |
| Greed | Increases Greed stat. |
| Growth | Increases Growth stat. |
| Increase Mana Cost +1 | Mana cost is increased by 1, so it can be used in a higher Combo. |
| Increase Mana Cost +2 | Mana cost is increased by 2, so it can be used in a higher Combo. |
| Kill Count | Deal current kills total as damage to a random enemy. |
| Leader | Attacks deal extra damage while the card is in your Hand. |
| Magic Hat | Beckons a dove from above. |
| Magnetic | Draws another of the same card, if you have one in your deck. |
| Mana Rebate | If the card would reduce Mana to 0, receive double Mana instead. |
| Midas | Playing cards earn coins while this is in your hand. |
| Might | Increases Might stat. |
| Mug | Earns coins when the card kills an enemy. |
| Nduja | Deals spicy damage. |
| Purple Trigger | Adds Purple color trigger. |
| Quick Draw | The card is always drawn first at the start of an encounter. |
| Rainbow | Adds all color triggers. |
| Recycle | Card skips the Discard pile. |
| Reduce Mana Cost -1 | Mana cost is reduced by 1. |
| Reduce Mana Cost -2 | Mana cost is reduced by 2. |
| Refund | Refunds Mana to play. |
| Restore HEalth | Recovers health after an encounter. |
| Retain | When the card is drawn, it stays in Hand until used. |
| Return | Returns to hand after playing. |
| Reverse Combo | Allows the next card to continue the combo while breaking the base rule of increasing mana ascendancy. |
| Triple Damage | Does three times the base damage. |
| Wild | Makes the card Wild. |
| Yellow Trigger | Adds a Yellow Color trigger. |
| Yin Yang | If you’re on even mana, you’ll gain 1 mana.If you’re on odd mana, you’ll draw 1 card. |
Which Gems are best for a damage-focused deck?
If you want raw hits, prioritize Double Damage, Triple Damage, Amount and Area. Double/Triple scale best on single-target weapons and evolve dangerously well with Evolution — those pairs often let you murder bosses before they get a second turn. Combine with Refund or Mana Rebate if you depend on repeating a heavy card.
How do Gems affect card combos and mana costs?
Combo rules are the invisible engine of every run. Increase Mana Cost +1/+2 pushes cards into higher combo brackets, which can be powerful if you plan your draw. Reverse Combo can break the typical mana ladder and create strange loops — treat it like a specialist tool, not a default choice. Countdown and Reduce Mana Cost gems shift when cards hit your usable window; pairing them with Retain or Quick Draw lets you time a repeatable burst.
Can I stack Gems or copy their effects across cards?
Yes, but with limits. Copy and Magnetic create multiplicative power on the same card type; Echo replays the previous card rather than the Gem itself. Recycle and Return change where a card lives, which changes how many times a Gem’s effect triggers per encounter. If you rely on card-synergy spreadsheets or a deck builder on Steam Workshop, test stacks in a controlled run rather than assuming scale is linear.
Character choice matters more than the table suggests: some characters multiply coins from Midas or turn Retain into a permanency engine. Watch Twitch creators who specialize in Vampire Crawlers for run-specific heuristics and join Discord groups to see what others are testing; Metacritic and community pages will point you to the most discussed builds.
Practical rules I use when drafting: refuse flashy single-use Destroy or Magic Hat unless you already have coin mechanics; snap up Refund or Mana Rebate if your deck runs 6+ cost cards; favor Recycle and Return on specialty cards you can tempo into every fight. I teach this to new players because a small decision in the draft table chains into the entire run.
Which Gem made you banish a run or carry it to victory most memorably?