Apparently, I have Google’s top result when people search for “Zombie CCG.” Because my initial ideas were sound, and I don’t see any reason I wouldn’t firmly grasp this sliver of internet relevance, I’m continuing that project.
Before I get into the specifics of what I'd want a CCG for any game really to do, I need to get into just what a CCG is and how it works.
CCGs are games in which any two players can meet with individually-constructed decks of cards pulled from an identical, larger pool and compete with one another to accomplish an in game goal to determine a winner.
Most CCGs have a few common elements:
Deck: This is where most of a player's cards come from during a game. Technically, a Deck is where a player usually Draws from to fill their Hand, either at the beginning of the game and/or during the game. In practice, the "deck" is used to refer to all of the cards a player brings to a match. This definition would include sideboard cards for Magic: the Gathering, or starting units for a game like Pokemon, Rage, or Star Trek, which have cards that begin in the Play Area and are never Drawn. World of Warcraft and certain versions of Magic also feature extra-large cards and/or additional decks which could never be shuffled into the Deck a player Draws from, but would still be considered part of a deck, as they're part of the set of cards that player brings to the game.
Hand: The second most basic part of a CCG. These are usually the cards a player has access to and can Play at any given point in time, usually held in their hand/hands/floor versus other cards that are usually kept on the table. To this day, the etymology remains shrouded in mystery. Management of these cards is an issue in and of itself in some games, with each player ensuring that they have more cards (and therefore more options) in hand than an opponent.
Discard Pile: This is where cards go when they are no longer playable. After a player has "used up" or lost access to a card, it is usually put into the Discard Pile, where it (typically) cannot be Drawn or Played again.
Play Area: This is where cards are used for their unique abilities and where most actions to win the game takes place. In Magic, there are two major Play Areas: the battlefield, which is populated by cards that remain in play (permanents) and the stack, which is populated by cards that are put into a Discard Pile after their effect is complete (spells). It should be noted the cards that remain in play usually represent something; either a person, a location, a piece of equipment, or even a broad effect or time period that affects other aspects of the game.
These four areas together represent a simple progression of play; a card travels from a Deck to a Hand to a Play Area. It will then either remain in the Play Area or go to the Discard Pile. While many games play with this, this progression is the basis for most CCG play. I believe the Star Wars CCG was the biggest departure from that, and it's to be lauded for its originality.
Drawing-Chief amongst play actions is moving the top card from a player's Deck to their Hand. It usually happens every turn and gives a player a new option, hopefully one that will move him closer to winning the game, or, at the very least, further from losing it.
Playing-Playing is how you utilize the abilities on cards in the game. Without the ability to put a card into a Play Area, a player cannot affect the Play Area (or the game). Even if it doesn't affect the Play Area or the current state of the game, Play actions are important.
Discard-Discard is the act of putting a card into your Discard Pile. For Magic players, "discard" refers specifically to putting a card into your Discard Pile from your Hand, but in a more general context, this covers everything from cards that usually stay in the Play Area being removed (often as a part of combat), or cards that don't stay in the Play Area being played and then put into the Discard Pile when their effect is complete.
Win Conditions-Finally, perhaps most importantly, is the fact that your game needs to end and it usually needs a victor. While there's nothing wrong with a Dadaist CCG made up of shuffled playing cards, coupons, and tags ripped off of mattresses, it requires either far more or far less nuance to successfully extricate oneself from such a game than most regular players of cards games would like. What the player is trying to do should be straightforward. Even if a game can tolerate multiple ways of winning, a player should pick one fairly early and have an objective in mind.
"Other Things" consists of Non-Card Elements. For me, the ideal CCG has no dice, no counters, and no life dial. It is simply a matter of having cards an playing them. However, additional options allows more latitude in resolving competing demands of design goals, and that's certainly hard to argue with.
Counters: Despite my reservations, sometimes using a jar of pennies is the only way to get business done. Damage counters, blood counters, mana, enhancement counters, status counters...CCGs almost need counters. They can be used to track victory conditions, reference abilities, or even represent other effects or objects in the game that aren't represented by cards(like Magic's token creatures).
Dice: Dice (including coins for coin flips) are sometimes used in games to determine random outcomes. The Star Wars system, if I remember correctly, used a set of numbers printed on every card so that players could use the cards of their decks for much the same purpose instead. As you can guess, I'm a fan of that.