Reactions and Traits

One of the most unique feature set of Card Hunter lies in its reaction mechanics. In fact, it is so unique that the developer diaries contain three chapters (Jon talks about reactions, Skaff Elias talks about reactions, developers talk about more reactions) worth of explanations on the history, motivation and implementation. Readers are advised to browse the links for in-depth information and key insights. Another distinct gameplay feature revolves around the mechanic. While card reactions provide a subtle way of streamlining gameplay flow, traits present more strategic deck building depth to the player. This guide presents some basics with regard to reactions and traits with examples of commonly encountered cards. Readers are advised to browse the Keywords guides for detailed information.

Reactions
A reaction consists of a trigger condition, trigger effect and a trigger result. A trigger condition refers to the state required for the reaction to manifest/activate. Trigger effect refers to the function of the reaction while the trigger result refers to the outcome of the reaction. As reactions are tied to actions/state of the game itself, bounded action space translates into bounded reaction types. There are currently five broad types of reactions in game (Table 1).

Traits
Unlike reactions, are not as complicated and follow simple rules. However, it has important and strategic significance in deck building and game play. A card bearing the keyword forces the player to play it when drawn. It takes precedence over all other in-hand cards and play is stopped until all cards are played. A player may select the order in which to play cards when multiples occur. A player cannot pass while holding a Trait card. Most cards are tied to attachments and therefore are subjected to the rule "any card that has to be attached to someone doesn't trigger from in hand". The real kicker of are:


 * Playing a Trait card does not end the player's turn.
 * When a Trait card is played, draw another card.

Traits as cyclers
Let's study the effect of the rule above. A single fully unlocked character in Card Hunter has a deck of 36 cards, regardless of race or class. When playing a game, you draw 3 cards in the first turn and 2 cards thereafter. It would take 18 turns to completely go through a character's deck once. Consider a deck where there are 6 trait cards and 30 non-trait cards in hand. As each trait card forces the player to play it and draw another card at the same time, the character's deck cycles faster. It would take 15 turns to completely go through the character's deck once. This means that the more cards that promote/allow automatic card draws, the faster the deck cycles through. Simple logic indicates that having multiple cards mean better hands on average. For a competent player, the ability to get better hands translate to better gains on average. cards are always synergistic with other card cyclers as they promote faster deck cycling. Inspiration, Demonic Feedback etc are classic examples of cyclers. Accumulate enough such cards in a deck and it becomes possible to draw the entire deck in a round. This is known as infinite draw. Infinite draws allow for deck abuse and make for very annoying gameplay.

In general, cards either exist on a boost or handicap. Boost cards that carry are generally build specific and provide synergy. Slicer is great for warriors that carry multiple chops. While Healing Spirit is designed for priests. Handicap traits are generally danagerous in some fashion or another. However, prudent deck design can completely negate the effect of the handicap. Mind Leak is annoying to a wizard/priest holding a ton of cards in hand. However, Mind Leak can be negated by blocks, Impenetrable Nimbus and melee cards. When a handicap trait is negated by deck design, it devolves into a cycler and the detrimental effect is reduced/avoided. Not all cards are detrimental to the card bearer only. Traveling Curse is an example of a handicap card that causes problems for the opponent as well. Having multiple Traveling Curses in a single game tends to keep the opponent on his/her toes. It is therefore important to design decks to minimize the effect of handicaps while exploiting the opponent's weaknesses.