One common criticism of Blizzard's Hearthstone from more experienced gamers is that actual gameplay is rather simple and not very interactive. There is a great deal of truth to this, especially compared to Magic: the Gathering. In Hearthstone, one player takes a turn and does several actions, while the other player watches. In some ways, it's like playing chess, but each side gets to take four moves at a time.
It is possible that this simplicity has helped Hearthstone's popularity. The decision tree is far simpler, and because several actions will occur on the opponent's turn, it's not worth predicting many turns ahead. It's much easier for a new player to play a turn at a time, and still string together a successful series of moves, giving them a decent chance of winning. In a more interactive game, the new player would fail to predict her opponent's responses, and end up making mistakes more often.
But if you've played Magic, Hearthstone does come across as overly simple. The big problem is that Magic's system for interactivity works fine when playing in the real world, but is absolutely horrific when translated to a computer.
Magic uses something called the "stack". When a player plays a spell or ability, the opponent gets a chance to respond with another spell or ability. This second ability goes "on top" of the first ability, and can be responded to in the same fashion. Thus a "stack" of spells is built, and when there are no more responses, the spells begin to resolve in Last In, First Out order, starting with the last played spell at the top of the stack.
For example, let's say Anna has a Grizzly Bear with 2 toughness. Betty plays Shock dealing 2 damage targeting the Bear. Anna responds with Giant Growth, giving the Bear an extra 3 toughness. The stack unwinds, and Giant Growth resolves first, making the Bear's toughness 5 in total. Shock then resolves and deals 2 damage to the Bear. That isn't enough to kill it, so the Bear stays alive.
You can see how interactive this simple example is, especially compared to Hearthstone. But when you translate this to the computer, it becomes very annoying, as Magic Online showed us. You have to ask the player if she wants to respond after every spell, and the player has to say no. Whereas in a real world game, only a few spells will actually have responses, and it's fairly easy for the opponent to interrupt and say they have a response.
The computer could skip asking responses if the player can't actually respond. However, that gives away information. Knowing that your opponent does not have a Counterspell or other response is a powerful piece of information.
This is the main reason Hearthstone is not interactive. Interactivity on the level of Magic is supremely annoying when playing a computer game.
Could Hearthstone have split the difference and made a more interactive game? Possibly. In the next post I'll outline another system used by other CCGs that might be a better translation for computer card games.
1. Yes, Magic players. This is a simplification of the stack. You can also respond to your own spells, and stop the stack as it unwinds and then add new spells to the top.