What card from another game would be ridiculously overpowered if brought over to Hearthstone?

Pretty much any yugioh burn spell

The monopoly It's your birthday collect $10 from all players would be preeeeeetty good. It doesn't advance the board state but it does get you enough cash to get a pack from heroic tavern brawl

Professor Oak from Pokémon - discard your hand, draw 7 cards. No cost.

Eat your heart out, "ancient one." Take a good long look.

The keyword "indestructible" means exactly what you think it does.

You could potentially translate it this way.

Funny, if you take small minions from this game and put them in MTG, they are generally totally busted. But take expensive ones, and the reverse is true. Probably because it is a slower game and getting to, say, 10 mana is really tough due to the mana system.

^{StillDiesToHexFeelsBadMan}

"Just say no" from Monopoly Deal

Curse! Lose your class from Munchkin. Your opponent loses its Class. He can not use class cards anymore.

THE MAGIC CARD POT OF GREED!

Red Card.

DIMENSION SHIFT

From Shadowverse.

Cost: 18 Play Points (mana)

Effect: Gain an extra turn after this one. While this card is in your hand reduce the cost of it by one (1) Play Point for every spell you cast.

So, basically you skip your opponent next turn for free in most cases leading to an instant lethal. The down side is not drawing it early, but the effect is so broken on its own that feels -balanced-. Imagine this in miracle/maly rogue or spell druid... jeez.

Hmm.

http://static.tappedout.net/mtg-cards/ravnica-city-of-guilds/glimpse-the-unthinkable_medium.jpg

Even if it was "just" a 2 mana "Opponent destroys the top 7 cards of their deck", it'd still be absurd for mill decks...

Gorz the Emissary of Darkness in Hearthstone terms

7 mana 10/9, demon When you take damage while you have no minions, summon this from your hand. If the damage was from a minion summon a X/X token, if it was from a spell deal X damage to your opponent.(X is the damage you took)

The Duelyst card Vorpal Reaver, 6 mana 6/6 windfury, deathrattle: summon 6 1/1 tokens.

There is chilean TCG called Mitos y Leyendas (Myths & Legends, well known on the south-american community as far as I know) and man there's some crazy shit in there.

• Treacherous Attack - 6 cost Spell: Take control of all enemy minions and give them charge but you lose the game at the end of your turn.
  
• Suicide Attack - 0 cost Spell: You get an extra turn after your current one but you lose the game after it.
  
• Hurricane - 12 cost, 12 attack legendary minion with charge, Battlecry: take control of all enemy minions. Once per turn you can remove a card you control to make a player discard 6 cards from their deck.
  
• Soortes - 10 cost minion, 22 attack with charge, bypasses taunt, inmune, at the end of each turn remove it from play.

Came here to see Pot of Greed as top comment. Leaving confused...

Beast king Barbaros

If we'd translate it to hearthstone terms:

Beast king Barbaros

0 mana 1/1

Choose one: Pay 4 mana, this card becomes a 4/5; or pay 8 mana, this card becomes a 9/9;or pay 10 mana this card becomes a 9/9, destroy all of your opponent's minions and all of their secrets.

And we also have his upgraded cousin: Beast Machine King Barbaros Ür

Beast Machine King Barbaros Ür

10 mana 12/12 mech

Charge

The enemy hero does not take damage from this minion.

Choose one: summon this card normally; or destroy a friendly mech and beast on your side of the field, and summon this card without paying mana; or discard a mech and a beast to summon this card without paying mana

Thundarus from Epic card game. 1 mana 10/15, other dragons have +5/+5 and let's say Unbanishable is like not able to Entomb in HS terms

Rampaging Wurm 1 mana 14/14 with charge

Not sure it would be OP or not but I'd love to see a Demonic Impact like card in HS

http://magiccards.info/ori/en/92.html

At the beginning of your upkeep, choose one that hasn't been chosen —

Demonic Pact deals 4 damage to target creature or player and you gain 4 life.

Target opponent discards two cards.

Draw two cards.

You lose the game.

Edit: or all the can't lose/can't win OR you win/you lose cards

http://magiccards.info/c14/en/132.html

You can't win the game and your opponents can't lose the game

http://magiccards.info/cn2/en/214.html

You can't lose the game and your opponents can't win the game

http://magiccards.info/7e/en/182.html

Take an extra turn after this one. At the beginning of that turn's end step, you lose the game.

The Triumvirate from HEX would be insane in HS. 9/9 minion with charge which would with every attack: draw a bunch of cards, heal you possibly to full health and drop a mini Flamestrike. Good luck :)

Phage from MTG

Conceal Rogue, nuff said.

Something like this probably. A MTG minion that is immune to almost everything

Giving Mages "Time Walk" from MTG.

Wheel of fortune from magic, Each player discards his or her hand, then draws seven cards 3 mana. Helps aggro and kills control and combo.

[The Exodia from Yu-Gi-Oh]. ^{Oh wait that is freeze mage ...(http://yugioh.wikia.com/wiki/Exodia_the_Forbidden_One)}

Probably the Chaos card from the Binding of Isaac. I mean....you can just insta kill your opponent

Joker, since it beats all cards.

Recently started playing The Elder Scrolls: Legends and every card with the text "if you have more health than your opponent" would be busted here. This one is a personal favorite.

Binding Of Isaac's Cards:
The Sun- Damage all present enemies and restore full health to the user.
The Joker - in exchange for some health you get your choice of (mostly good) special items (each with a cost).

mirrorforce from yugioh: Secret

When an opponent minion attacks, destroy all your opponents minions.

Skip from Uno. That would be some bullshit.

The other Big Game Hunter

Swords to Plowshares. If you thought Execute was overpowered...

counterspell

Yugioh ... Qliphort Tower. In HS i would be: 8 Mana 9/12. Other Minions have -0/-2. Cannot be Targeted by Spells or Minions

The MtG equivalent of Twisting Nether only costs 4 mana.

Most already good MTG cards are completely busted when translated over to consistent mana and card draw in hearthstone. Off the top of my head since I quit magic a while ago, this is completely insane. Also this makes your entire board indestructible for 8 mana and is also an 8/8 in stats.

Most level 4 or less monsters from Yu-Gi-Oh. Most of them should have more than 30 attack (due to most game numbers being calculated in the hundreds or thousands) and being level 4 or less means there is no cost to play them.

Kuriboh from Yu-Gi-Oh. 1 mana 300/200. Pretty OP.

Yugioh's Swords of Revealing Light. Did someone say freeze mage?

The Old Maid

12 Mana 10/10

Text: If this is the only card in your hand, lose the game.

Mirror Force from YGO as secret. Or... lets say almost all traps from there

Uberdragon bajula (from duel masters). Destroys two mana crystals whenever it attacks.

Pot of greed

Any Yu-Gi-Oh card. Weak monster with like 100 attack or something on turn one :⁾

I'd love a "Donate" card in HS. But I wouldn't be surprised if the devs were too scared to see what we would do with it...

Or even more op, EX Pikachu XY124. The Iron tail attack...

This would be even worse than pre-nerf Yogg... " Flip a coin until tails (tails stops the combo) add 30 damage to this attack if heads. If heads flip coin again. " So yeah it can deal an infinite number of damage if lucky enough so if we "translate" this to Hearthstone it would probably 3 damage instead of 30 damage so 10 coin flips with heads and you would basicly win the game... [So at a 0,09 percent chance of winning the game at turn 1 ;going face] (+ this would be a 1 mana card)

This could target a minion but the way Pokemon works i would say that this card would be able to choose a target yourself.

Setting aside all of the card draw cards, Rayquaza-EX from Pokémon would be pretty busted. In Hearthstone, it would basically translate to "When this minion attacks, destroy as many Mana Crystals as you like and gain +5 Attack for each crystal destroyed." And in Hearthstone, you have a singular target to focus on to win.

Eternal witness, 3 mana 2/1 bring back any card in your graveyard.

I dont know what the card was, but it was a magic card that allows you to draw 2 cards from your deck and put them in your hand.

Man there are a lot of good ones here, but there is one card that really stands out above the rest for me in terms of just how absolutely and utterly broken it is. In fact, it's one of the few cards in the history of MTG Vintage that has been brought up as a potential Ban.

Let me introduce you, to Yawgmoth's Will: http://gatherer.wizards.com/Pages/Card/Details.aspx?multiverseid=5629

Essentially you can read this card as drawing every single card that is in your graveyard. For 3 mana. Suffice to say in Hearthstone where resources are far more finite, being able to recur your entire graveyard would be fucking insane. The fact that it is free with Preparation only makes it that much more disgusting.

It's really difficult to translate to my favorite CCG of all time, Star Wars CCG by Decipher, since it plays much differently than a lot of current CCGs. The game hasn't been in print for 15 years, though there's still a community that designs new cards and a sizable following for something not sold for that long. But here goes:

http://www.starwarsccg.org/cardlist-beta/img/Tatooine-Dark/darthmaul.gif

Darth Maul, the ultimate control card! Maul is an 8 mana 7/6 (6 mana if the game board is Tatooine!). During your turn, before attacking, you can discard a card from hand: both players Joust two cards, and the lower total (Maul or opponent's Jedi) is killed. Risky, since Jedi would be found in other control decks, but if you win, it's a sweet reward.

But the best part, if the opponent has no 4+ health minions in play, they're all health=0, so he's an 8 mana 7/6 that can immediately clear the opposing board if they don't have a 4+ health minion in play. Plus, he's immune to attrition (we'll call it spell damage for this exaggeration) less than 5, so if he gets onto the board and clears it, he's also sticking around for awhile.

monastary swiftspear from mtg. a one mana 1-2 with charge and "whenever you cast a spell gain +1 +1". Op with preist

How about Black Lotus?

Platinum angel. "Your opponent can't win the game. You can't lose the game"

3 mana 18/10 SeemsGood

Fusionist.

900 ATK point with Charge?! Sign me up!

http://gatherer.wizards.com/Pages/Card/Details.aspx?multiverseid=83597

Drained Blade from Ederon, another card game I used to play. I just hate this card.

Share the pain from yugioh for warlock, i destroy my villager for your antonidas

Wargames

Phage from MTG (google it, I can't link because mobile) + conceal = gg

If the mechanics for it were sorted out, Kuriboh from yugioh, ignores damage completely and would make freeze mage or any control deck, well, really any deck, MUCH more broken.

Sea Titan from Epic Card Game comes to mind. 1 mana, 11/14, Untargetable, Battlecry: Sap.

I want to see a version of this where seemingly amazing cards are twisted into something awful, like a genie's wish. In this case, Untargetable includes the mouse cursor, so you can't attack with it.

Pot of Greed...

And basicly any regenerate ability on big minions in HS is op as crap. (form mtg)

If you played MMDoC you may remember this card. You could have 4 of these in your deck.

Of all the cards in MTG and you pick Act of Treason? How about Black Lotus? Ancestral vision? Bolt?

Shauna from the Pokémon TCG would be wild. Shauna takes your hand shuffles it into your deck and draws 5 cards.

Pretty much anything from the eldrazi sets with "annihilator" on them.

Imagine that annihilator 6. This means your opponent must destroy either creatures, or mana resources, whenever your creature attacks. In this case, it would be mana crystals. Going from 10, back down to a static 4 would be game-ending.

If they also happened to have a card for double strike, as well, you're looking at either a a wiped board, or resetting at 1 mana crystal.

Lysandre's trump card from pokemon would be pretty good as well, especially in decks like discardlock.

"Cheat" from Munchkin

Exodia

Scrap Iron Scarecrow was a trap card in yugioh that nullified whatever monster was attacking and then re-set itself. You'd essentially just cancel out your enemies attack phase permanently until they played a card to destroy/nullify trap cards. As a secret it'd be along the lines of (When an enemy minion attacks, stop the attack. This secret is then played again)

Blast Gloves from Magi-Nation: 0-mana double the damage of the next spell you cast.

http://bluefurok.com/AWImages/blast_gloves.jpg

Don't remember the cards name, but Shadowverse has a better FoN+Savage combo: for 8 mana you get a 13/13 with charge, which doesn't even die at the end of the turn, I'm not sure how the thing is considered balanced in there but in HS it would be nerfed for the same reason combo druid did.

Blue-Eyes White Dragon from Yu-Gi-Oh does 3000 damage and has 2500 HP. Pretty much all Yu-Gi-Oh minions would be ridiculously OP.

Yata Garasu: (Atk 200, Def 100, 2 stars) For anyone who didnt play yugi thats shitty stats.

This card cannot be Special Summoned. This card returns to its owner's hand during the End Phase of the turn it is Normal Summoned or flipped face-up. When this card inflicts Battle Damage to your opponent, they skip their next Draw Phase.

To hearthstone with charge would be absolutely broken.

Avatar of Yuanshi from Infinity Wars would be pretty good. 7 mana 10/10, ignores taunt, gets +10+0 at the end of your turn and cannot die.

Pot of Greed: Draw 2 cards.

This guy right here: http://magiccards.info/scans/en/fvl/9.jpg

The Joker

If it wouldn't be Heartstone-ified, Cardfight Vanguard cards would basically be an instant win, being 11000/11000's that could attack face instantly. ^{DiestoBHG,literallyunplayable.}

If it would actually be Hearthstone-ified, then I guess the old "Dragonic Overlord" would be OP, even though it's pretty bad in Cardfight Vanguard now a days.

Dragonic Overlord

0 mana 11/11 - Dragon

Charge. Ignore Taunt.

When this card attacks, can't be damaged. When this card is attacked, deal the damage to your hero instead.

When this card attacks, draw 2 cards.

You may use 3 mana crystals, if you do this card gets until the end of your turn: +5/+5, and after this card attacked and dealt damage you may attack with this card again, but then this card draws only 1 card instead when it attacks.

This card has -2/-2 if you don't have another Dragon on the field.

Levy AR Lab Access from Android:Netrunner.

Basically shuffles your graveyard into your deck, resetting your deck. Would be an autoinclude in any control deck

You guys are joking right? Have you met Charizard?

0 Mana 120HP 100 damage, GG.

Kuriboh. OMG 300 damage in the face !?!?!?! 200 Hit points !?!?!?

Chaos Emperor Dragon - Envoy of the End You can pay 1000 Life Points; send all cards in both players' hands and on the field to the Graveyard, then inflict 300 damage to your opponent for each card sent to the Graveyard by this effect.

I don't know much about other card games but I've heard Magic The Gathering had a meta defining a cheap spell called Thoughtseize which lets you look at your opponents entire hand then pick a card and discard it.

To me this seems similar to thought steal since it gives the player information, however I think thoughtseize is much better since you can see your opponents entire hand for more information, then make a decision on what card to remove.

Is your opponent playing a combo deck and is hoarding pieces? Goodbye Thurassian/ Malygos or Gadgetzan Auctioneer. I imagine it would also be handy stopping your opponent playing on curve or playing high value cards.

Tendrils of Agony in Rogue.

It reads "Target player loses 2 life and you gain 2 life Storm (for each spell cast this turn, copy this spell)".

Coin, coin, coin, prep, tendrils, tendrils is a 44* point swing.

The ace would be pretty good - it's ability to act as both early game and late game could offer some much-needed flexibility to control decks.

What would this even do in Hearthstone? Switch your opponent for another in the queue if they hit you with a minion?

Dragon Ball Z Cosmic Backlash - Physical att. your opponent draws 5 cards. if successful and you did not declare a toku-waza you win the game.

not really a popular card game but a 7 mana 7/7 charge 3xwindfury would be quite decent in hs http://infinity-wars.wikia.com/wiki/Agent_Coyle,_Firestarter

If any of you have heard of a card game called epic, literally EVERY card is busted. Which kind-of means that none of them are busted in comparison to eachother.

0 cost charge, battlecry: your opponent discards a card and you draw a card.

Whenever this deals damage to a hero, your opponent discards a card and you draw a card. 1/2

Time walk seems pretty good.

Exodia.

From Redakai, Conquerors of Kairu:

Kairu Destroyer. 4 mana spell. Silence a minion, or destroy a hero's hero power. Draw two cards.

Exodia

True-Name Nemesis
It literally can't be stopped by your oponent, and HS has no means of dealing with such mechanics.

In Yugioh, there's a passive effect some monsters have called "not affected by Spell/Trap (or possibly monster also) effects that do not target this monster". Could you imagine a minion unaffected by Flamestrike or Twisting Nether? Granted, that may be too specific of an ability to be useful beyond a tech choice....but I think it would fuck up the flavor of many mass removal cards. We are better off with stuff like Burly Trogg/Gallywix which can make an opponent reluctant to use big spells. Let's not even consider "not affected by minion effects" being a thing in Hearthstone ever- it works for Yugioh but has too many game breaking implications for HS.

From Arkham Horror LCG (http://arkhamdb.com/card/01057) pay 3 mana get 10 mana.

The Ace of Spades

Oh, good old Mind Twist from Magic oughta do it.

http://www.hearthcards.net/cards/0b5e027d.png

The Erase is pretty broken. Sakura was able to capture this Clow Card with the help of Syaoran, but as far as game mechanics go, this is a removal spell that can target anything, including your opponent.

Black lotus

http://m1.artspace-static.com/media/a-s/artworks/jim-thompson/None-293068255265/jim-thompson-milles-bornes-puncture-proof-800x800.jpg

Thousand-Eyes Restrict from Yugio.

 

Once it's played, no other monsters but itself can attack. Then, once per turn, you can take control of an opponent's monster and equip it to Thousand-Eyes Restrict. That card becomes Thousand-Eyes Restrict's attack and defense and if you try to kill Thousand-Eyes, the card that's equipped to it is destroyed instead.

4s from Truco (look it up)

It pretty much would be a spell no cost win "That round"

Aka, the game

Gift Card from Yu-Gi-Oh. heal opponent 3000 life with Auchenai or Embrace the shadows

Ookazi, it could even kill control warriors

Pot of Greed - Allows me to draw 2 cards from my deck!

Black Lotus! Most expensive card for a reason.

Black Luster Solder - Envoy of the Beginning

8-cost 10/8

Reduce this cost by 4 if a battlecry and/or deathrattle minion has died this game. If this minion attacks and destroys a minion, it may attack once more this turn. If this minion does not attack, at the end of your turn, destroy a random enemy minion.

Seems about right. Fuck that card into the ground, burn it's mother, and sodomize it's father with a flaming backwards porcupine.

edit How about some more?

Relinquished

1 0/1 minion

Cant attack. At the end of your turn, a random minion your opponent controls gains "can't attack", and this card gains it's attack and can now attack.

Lord of D

4 mana 3/5

Friendly dragons can't be targeted by spells or effects.

Obelisk the Tormenter

11/11 10 mana minion

If you place this minion between two others, destroy them and all of your opponent's minions too.

Yata-Garasu

1 mana 0/1

If this minion attacks directly and deals damage, your opponent skips their draw. Return this minion to your hand at the end of the turn.

Dark Necrofear

8 mana 5/9 (demon)

Deathrattle: Random opponent's minion is now yours.

Summoned Skull

6 mana 8/5 (demon)

Jinzo

6 mana 6/6

Secrets can't activate.

Mystic Tomato

4 mana 4/3

When this minion is destroyed by battle, summon a.... wait a second....

Painful Choice

3 cost Warlock Spell

Your opponent discovers a card from your deck. Your hero power now draws that card.

Axe of Dispair

3 cost 3/2 weapon (demon)

Deathrattle: Pay 5 health, re-equip this weapon.

[removed]

Blue Eyes White Dragon

8 Mana, 3000 Attack, 2500 Health. Just saying.

The Ace of Spades

The Ace of Spades

Not OP but Elder Scroll Legends has a few more mechanics which would be funny in in hearthstone.

Minions can have the keyword drain, which means everytime they attack, they heal the damage dealt back to a player.

So imagine an arcane giant with drain. Every time it attacks you get 8+HP.

Another keyword is regenrate. After your turn, and the enemies turn. It goes back to full health.

Finally is pilfier. Which means everytime you attack face something happens. One card would read like this.

Thief:

Mana cost: 6 Attack: 4 Health: 4

When you attack with this creature, give the player health equal to the damage dealt. When this creature attacks the enemy player give it +4/+4.

So give this creature windfury and on 1 turn it does 12 damage and heals for 12. On the second turn it will do 28 damage and heal for that much.

Essentially every creature from MtG, assuming blocking mechanic comes with them, being exclusive to certain classes would be OP. Instants would also be overpowered if let's say only Mages and Warlocks have access to them.

Not a specific card but pendulum monsters from yugioh. They are like a kel'thuzad/resurrect deck but meta.