Card Hunter Infinite Draw Decks Analysis

Card Hunter Infinite Draw Decks Analysis by karadoc

This is going to be a long post. Here’s a list of the topics I intend to cover:

• What is an infinite-draw deck?
• Why is infinite-draw bad for the game?
• What makes infinite-draw possible?
• What can be done to prevent infinite-draw?

The key point of this post will be a set of item design guidelines for Blue Manchu which will make infinite-draw decks impossible without changing any of the existing game rules. This will be in the final section. (ie. ‘what can be done’)

What is an infinite-draw deck?

An infinite-draw deck is a set of cards which allows the player to play an unlimited number of cards in one round by continuously drawing new cards from their deck. With such a deck, the player will typically be able to have all 36 cards from one of their characters in their hand at one time. With an infinite-draw deck, once the player draws the right cards to begin their infinite draw combo they will be able to continue playing and drawing new cards indefinitely, regardless of any unlucky draws.

Why is infinite-draw bad for the game?

In single-player games, infinite draw is not really a problem. But in multiplayer it is a big deal. If a player is ever able to start an infinite-draw combo in a multiplayer game, their opponent won’t be able to do anything at all. The infinite-draw player will just continue to play out their combo, for however much time it takes, while the other player will have no choice but to continue pressing ‘pass’ until the game is over. As long as the infinite-draw player has at least 1 card that can damage the enemy, and at least one card to move their own character, then they will win the game eventually. This is bad for balance in that the infinite-draw combo is undefeatable once it gets started – even if the combo is difficult to get started, the fact that it can be done and that it will always win the game is enough for it to be considered imbalanced in the extreme. And it is certainly bad for gameplay, because it will result in one player doing absolutely nothing while the other player just plays cards in a systematic and repetitive way to continue their combo and win the game. So I believe it is vital that the game is designed in such a way that infinite-draw is impossible, for balance and for fun.

What makes infinite-draw possible?

Infinite-draw is made possible by cards which allow the player to immediately draw additional cards, so that they can increase the total number of cards in their hand. This includes cards such as Inspirational Thinking, Inspiring Presence, Unholy Power, and Demonic Feedback. For example, if you imagine a deck which has nothing but Inspiring Presence in it, it’s easy to see how this would allow you to draw cards indefinitely.

It’s important to understand that these cards on their own aren’t necessarily problematic or too powerful. The problem arises from the synergy of having many such cards in the same deck.

Obviously it is impossible to have a deck with nothing but Inspiring Presence, because there is no set of items with only those cards. But there are sets of real items currently in the game which do allow other infinite-draw builds. Here is one example, created by turinturamba. (I’ll quote the cards from this example shortly.)

The key feature of an infinite-draw deck is that playing each of the cards in the deck must allow the player to draw at least as many cards as are in the deck. For example, Inspiring Presence allows the player to draw 3 cards; Demonic Feedback allows the player to draw 1 card; Spin Around allows the player to draw 1 card; Hot Spot doesn’t allow the player to draw any cards. If you add up the number of cards that can be drawn by playing every card in the entire deck, you can determine whether or not it is an infinite-draw deck. A deck of 36 cards which allows the player to draw 37 cards is an infinite draw deck. A deck which only allows the player to draw 25 cards is not*.

Note: effects which require some condition or delay for the player to draw a card typically cannot contribute to an infinite combo. For example Accelerated Thought and Consecrate Ground cannot contribute, because they both require the player to end their turn in order to draw a card. Similarly, Martyr Blessingand Parry cannot contribute, because they both require the enemy to attack in order to draw a card. Thus these four examples would count as ‘draw zero’ for this analysis. On the other hand, Cleansing Ray would count as draw 1, because the player may be able to supply themselves with terrain attachments to cleanse. Similarly, Demonic Feedback would count as draw 2 regardless of the damage it does. The damage isn’t a problem because it can be absorbed / healed by other cards (eg. a single Impenetrable Nimbus is enough to negate all of the damage from unlimited uses of Demonic Feedback.)

So lets go through the cards from one of the characters in turinturamba’s build to count how many cards they will allow us to draw:

Adding these up, we get 3*2 + 2*1 + 3*1 + 3*1 + 3*2 + 2*4 + 6*1.5 = 37. So with this build we can draw 37 cards, and since that is more than the 36 cards in our deck it is an infinite-draw deck. Note that it is generally unimportant which of our character actually draws the cards, because we can assume that the other characters are using either the same deck or some other deck which can make equally good use of the card draws.

What can be done to prevent infinite-draw?

Clearly it would be possible to introduce new game mechanics which prevent infinite-draw from working. For example there could be a rule that simply prevents more than, say, 8 card from being drawn by any one character in any one round. But I think it’s better if we can prevent infinite-draws without introducing any new arbitrary ad hoc rules.

I believe the best way to prevent infinite-draw decks is to simply make sure there is no possible set of items which have enough draw cards to create an infinite-draw deck. However, clearly it would be a chore and a burden on designers if they had to re-evaluate every possible item build to look for infinite-draw decks every time they add a new item or change an existing item. So I’ve come up with an easy-to-follow rule for item design which, if honoured, would ensure that no infinite-draw decks are possible. The rule is this:

No single item should allow more cards to be drawn than are provided by the item.

For example, a three card item should not allow any more than three cards to be drawn; and a six card item should not allow any more than six cards to be drawn. (Technically, to be completely immune from infinite-draw builds, the rule should be that items don’t allow even allow an equal number of cards to be drawn. But I’m confident that the rule wouldn’t need to be that strict to be effective; and I’d prefer to not be so restrictive about what items are possible.)

If there were no items in the game which allowed the player to draw more cards than are on the item, then clearly there would be no set of items which allowed the player to draw more than the 36 cards in their deck. So if this rule is followed when designing items, then infinite-draw will not be a possible.

Important note: when counting the number of possible cards that can be drawn, we should always consider the ideal usage of the cards. eg. assume that we can handle any self damage from Demonic Feedback; assume that we have a full team of dwarves if we’re using Dwarven Battle Cry; assume that all our characters will be in range of Inspiring Presence; and take into account any traits which could result in additional draws. Cards such as Talented Healer andAltruism complicate the analysis somewhat because they add draw effects to cards which usually wouldn’t have them. For the ideal case, we must assume that the character has access to both these traits unless we are certain that there is some other game rule or effect which prevents the character from having them. For probabilistic effects (such as from Altruism), we should use the average number of cards drawn.)

As a final example, lets consider the items used in turinturamba’s build to see which of the items violates my rule:
Aureate Mace: 6 cards, 3 draws (from Inspiration with Altruism)
Inspirational Mail: 3 cards, 3 draws (from Inspiration with Altruism)
Heavy Wooden Shield: 3 cards, 0 draws
Spinning Top Boots: 3 cards, 2 draws (from Spin Around)
Demon Charm Of The 2nd Circle: 3 cards, 5 draws (2 from Unholy Power, 2 from Demonic Feedback and 1 from Demonic Revenge)
Advanced Flexibility: 3 cards, 8 draws (8 from Leadership)
Focused Piety: 3 cards, 3 draws (from Altruism)

So there are just two items used in this build which violate my rule, and thus make this particular infinite-draw deck possible: Demon Charm Of The 2nd Circle and Advanced Flexibility. (Note that turinturamba use Demon Charm Of The 2nd Circle in every divine item slot.)

This doesn’t necessarily mean that Demon Charm Of The 2nd Circle and Advanced Flexibility need to be changed. It’s not necessarily a catastrophe if an item violates the rule. But it is important to understand that any item which violates the rule creates the risk of an infinite-draw deck. And in this case, it is these two items that make turinturamba’s infinite-draw deck possible.

Regarding Leadership; although this card requires the player to discard 4 cards in order to draw 4 cards, that doesn’t negate the problem. Remember that we need to consider the ideal usage of each card for the rule to be reliable. In the case of Leadership the ideal usage is that we discard 4 draw zero cards from our hand — cards that we no use to us anyway — and thus the discards don’t negate the fact that we can draw 4 new cards. This makes Leadership particularly problematic because even if there was only 1 leadership card on any human skill item, it would still be a draw 4 card on a 3 card item and thus violate the rule.

A variation on the golden rule.

The rule I proposed is that every individual item should not allow more draws than it has cards. This rule is sufficient to guarantee that no infinite-draw builds are possible, but it isn’t the only way. And as I pointed out, with that simple version of the rule it is not possible to have Leadership on any human skill item without violating the rule. So it may be worth considering adjusting the rule so that it can guard against infinte-draw without completely prohibitingLeadership.

One possible variation on the rule is to assign each item slot with a particular draw quota, and just make sure that the sum of those quotas is less than the total number of cards. For example, the total draw quota for priests could be assigned as follows:

2x divine weapon – 4 draws each
3x divine item – 3 draws each
1x divine armor – 4 draws
1x boots – 2 draws
1x shield – 2 draw
1x divine skill – 3 draws
1x race skill – 8 draws

In this case, I’ve reduced the allowable number of draws for divine weapons, boots, and shields; and given those additional draws to the racial skill and to divine armour. Any kind of distribution like this is just as effective as the original rule so long as it is applied consistently to all items. (eg. in this case the rule would disallow any kind of shield which allows the player to draw 3 or more cards.)

With the distribution I’ve chosen here, I think you’ll find that almost every item in the game is already allowable, including Advanced Flexibility. But Demon Charm Of The 2nd Circle would still violate the rule, so I suggest that item be changed.

Finally, let me just reiterate that the kind of rules I’m proposing for item design are not the only way to ensure against infinite-draw decks; but it is a relatively simple approach which doesn’t require any changes to the game mechanics and which doesn’t require item anyone to study every possible item combination to see if there are any problematic cases. I strongly suggest that a rule like this be adopted and enforced – and that any items violating the rule be modified so that they are compliant.

That’s all.

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(* Note: it is actually possible to create an infinite combo even if the total number of draws for the deck is slightly less than 36, because cards that are in the player’s hand already don’t need to be redrawn and thus don’t need to be part of the infinite-draw combo. Because of this, it may be wise to keep the total draw quota below 32 rather than 36 – to account for the 4 cards that a player can have from their deck at the start of any one round without any bonuses. This is not something I’ve considered in detail for this analysis.)