So you want to make a Collectible Card Game, eh? Well, good luck. CCGs have long been stereotyped as being "nerdy" or "kiddy" games in the public mind. Breaking past this stereotype is going to be difficult, and designing a game that deserves to will be harder still.
First, be sure to check out Write a Story for basic advice that holds across all genres. Then, read our "Collectible Card Game" article for a rundown of the genre-specific tropes that will help you, hurt you, and guide you on your way.
The "magic word" in designing CCG is Play. Don't just play your favorite CCG — in fact, put it aside for at least a month. Instead, go to the bookstore or local gaming shop or comic book store and try new Tabletop Games. Play Dungeons & Dragons, or watch people doing Warhammer 40,000. Watch Wil Wheaton's show Tabletop on Geek & Sundry. Compare Chess to Risk, Monopoly with Settlers of Catan, Munchkin with Apples to Apples. If you're going to create a new game, you need to know what pre-existing games are already doing, so that you can avoid the things you don't like and steal the things you do. Plus, you'll have fun — and isn't that the point of gaming?
- Crack Is Cheaper. Tropes Are Tools, including this one. First off, the more cards the consumers buy, the more you can afford to create follow-up product, thus resulting in more income; exploit this node, and you're all set. Second, the day players start shelling out ridiculous amounts of cash for individual power cards — the day players like your game so much that they are willing to blow extra money on it — is the day your game has actually succeeded. CCGs have Revenue-Enhancing Devices built into them. Exploiting this sounds dirty, but you need to do it anyway.
- Bribing Your Way to Victory, Screw the Rules, I Have Money!: These are built in default into the existing Collectible Card Game / Trading Card Game model. Because packs usually contain a random assortment of cards, players who spend more money on the game are more likely to have more powerful cards. Having said that, Fantasy Flight Games (A Cardgame Of Ice and Fire) have pioneered a new distribution method they call a "Living Card Game," where cards are sold in pre-sorted packs with contents listed on the back of the box. There are no randomly-assorted packs for sale. According to FFG, this helps you avoid wasting money, and emphasizes skill in playing and deck-building over luck.
- Expansion Pack: This is the main trope that keeps your consumers playing. For one, it provides novelty and variation. They prevent the game from being monotonous, keeping your fanbase intact. Second, people like new stuff — this is a scientifically-proven part of human nature. A game that constantly releases new stuff has a powerful and addicting quality.
- Complacent Gaming Syndrome: Expansion packs, and to a lesser extent banlists and rotating formats (if you choose to have them), will also help prevent your game from becoming static. Witness the phenomenon of the "solved game" — games in which the correct choices, the ones that always result in a win or at least a forced draw, have already been identified. While CCGs are typically a bit too complex to truly "solve," there will always be Game Breakers that essentially serve the same purpose: choosing not to play them is suicidal because they make it that much easier to win. The first answer is the Obvious Rule Patch, where you simply ban that card from (supervised) play... but once one is gone, another takes its place as strategies shift and decks are redesigned, and if you keep banning those, then eventually the game simply isn't as fun anymore because there are only three cards still legal for play. So the better answer is, don't just remove the old ones. Add new ones. And then do the cycle all over again, yeah, but frankly that's your lot in life, now that you've decided to build a CCG: monitoring as many matches as you can and taking statistics on which cards have a higher-than-normal win rate. Have fun.
- Awesome, but Impractical. It is important to have deployment limitations, slowing the game down and preventing players from putting really powerful things in play right at the start. Only one card game didn't do so: First Edition Star Trek: The Collectable Card Game. It was a disaster. Under normal circumstances, you could only play one Ship or Character per turn, meaning that some Red Shirt was worth the same as the Enterprise herself; and the Event card "Red Alert," which let you play any number of cards per turn, became a Game-Breaker of ludicrous proportion. The second edition of the game put a resource system into play, which was a lot more sensible.
- The cost itself can be variable. Magic and Pokémon only let you play one new Mana a turn, which delays powerful attacks for a few turns. However, this built an additional Weaksauce Weakness into the game: if you simply didn't have Mana to deploy, or your opponent was able to destroy it, you were screwed. Legend of the Five Rings let you play as many "Holding" cards, which provide "Gold" for purchasing other cards, as you wanted, but each Holding itself costs gold, and furthermore your handnote is only four cards large. Decipher's The Lord of the Rings card game used an innovative "twilight pool" mechanic: playing good-guy cards added points to the pool, and playing bad-guy cards removed them.note In other words, you could only do good stuff for yourself at the cost of enabling the opponent to do good stuff for themselves. And ST:2E gave you a permanent limit of seven points each turn, which you could spend on playing cards from hand (each card had its point cost clearly marked) and/or drawing cards into hand (1 point per card).
- Card maximums. Originally Magic didn't have a limit on how many of Card [X] you could have in a deck. So people would go in with decks consisting solely of like 20 Swamps and then a Zerg Rush of Plague Rats, which could get out of hand really quickly. Nowadays, Magic decks can only have 4 or less copies of a single card (sorting by name) unless that card is a basic land, and almost every other CCG out there has some limitation on multiples. (Some games do it by marking the individual cards themselves if they can't be multiplied; under such circumstances, you can have infinite [This] or infinite [That], but those cards tend to be really, really weak anyhow, and you wouldn't play a lot of them except for the lulz.) This means you can't load your deck down with whatever card it revolves around. It also slows the game down: if you can only have four copies of your central card, you have only a 1-in-15 chance of drawing it.
- Collectibility / Customizability / Competitive Balance / Variable Player Goals. One of the big appeals of this genre is that you can design a deck to pursue a particular victory strategy. What that means is that there needs to be more than one way to win. Most Magic duels revolve around getting the opponent from 20 Hit Points to 0, true, but each of the five colors has different philosophies and tries to get there in different ways; and there's always milling or the various Golden Snitch cards like Barren Glory or Coalition Victory. In LotR above, you could win by tossing the Ring into the fire or by knocking out every other player's Fellowship. And let's not even talk about L5R and its four different ways of winning.
- Faction Calculus. One of the fun things about a CCG is building out a strategy which (you hope) will win you the game, and then testing it against someone else's. But people also bond with their favorite factions, philosophies, and characters. Having factions also builds into your profit margins, because (unless you've gone with the LCG model) every time player opens a new pack, at least 50% of the cards in it are useless to his current deck. You want more than one side.
- Choices Vs. Options. First, we acknowledge that we are ripping off MaRo, so read the article in his words if you'd prefer. But there is a difference between "Options" — "You can have both A and B" — and Choices—"You can only have A or B, pick one." You want Choices instead of Options. Not only should this shape the design of individual cards, but the entire deck-building aspect of card games is about Choices: there are so many cards available that you simply cannot create a deck that uses all of them. Faction Calculus adds to this by further striating the available strategies, which is another reason why it's good. But the point is this: you want Choices because those provide limitations. And the entire heart of gaming is about finding ways to overcome limitations. That's why we have Min-Maxers; that's why we have Munchkins; that's why we have "Stop Having Fun" Guys. Say what you want about their attitudes, but they want to overcome the game, because that's what gaming is. So don't give them Options. Give them Choices. Make it that much harder — and that much more fun.
- Deck design. Look, it's the truth: this is your deck. There are many like it, but this one is yours. If you're reading this article, you've probably designed a few decks in your time, regardless of which CCG you play. Players can get emotionally invested in their work. So giving them the tools to put their own mark on the metagame can only result in further investment on their part. Of both time and money.
- Most CCGs are adaptations of existing franchises, for reasons that will be discussed in the next section. The only exceptions are Magic, Legend of the Five Rings (the RPG came after the CCG), Yu-Gi-Oh! (which itself is, by Word of God, a Magic ripoff) and... Well, that's about it, at least where popular franchises are concerned. (I mean, have you heard of Magi-Nation?) Decipher Inc came up with three very good adaptations—LotR, Star Trek: The Next Generation (eventually expanding to all the rest of the franchise save the 2009 pre-boot) and the Star Wars Customizable Card Game—but not a single one of them is in print today. And nobody needs to talk about Pokemon cards. The point is that CCGs are not exempt from The Problem with Licensed Games. The rebuttal is that creating your own Intellectual Property is just as challenging or more so... but again, we'll talk about that further down.
- The player. In most CCGs, the player is a non-entity who only kind of interacts with in-game entities. The Planeswalkers of Magic: the Gathering, for example, can be attacked but cannot defend themselves; in Pokemon you don't even fight your opponent directly, but instead his mons. Likewise, the Star Wars, Star Trek, Lord of the Rings, Game of Thrones, Babylon 5, Wheel of Time and Wing Commander card games don't feature any entity corresponding to the player at all; victory is determined by other means, often Scoring Points. Just about the only exception is Hearthstone Heroes Of Warcraft, where you choose a character class and that class is then represented as an in-game entity. He or she can not only be attacked, but—if equipped with Weapon cards—can attack as well. The logistics of incorporating the player into the game as an in-game entity are confusing, but it's a design space that hasn't much been explored.
- Number of Players. Star Wars, Star Trek and Pokemon can only be played with two players. Period. The rules simply don't accommodate anything else. While this is the sound of the devs taking the easy way out, the truth is that designing a CCG to support multiplayer (by which we mean, "Three or more players") can get crazy—the cards that say "Target opponent does [X]" become weaker, while the "All opponents do [X]" become insanely powerful; politics and the Kingmaker Scenario get involved, where you start deciding whether to use the beneficial cards on yourself or on your maybe-allies; and so on and so fifth. See all this chaos? One of the things you should decide on, as early as possible, is what the maximum number of players per match is, because this will inform your design decisions. Choosing to go 2P only will make the game more boring, but also easier to design.
- Necessary Materials. Every CCG needs a flat surface to be played upon, but some require more, and such requirements are generally perceived to be Scrappy Mechanics because they reduce the portability of the game. One of the nice things about a CCG, after all, is that you can just stick your deck in your pocket and be able to play just about anywhere... which isn't going to be true if you additionally need dice, or a bunch of little counters, or pen and paper, none of which may near to hand. The easier your game is to play (up to certain maximums), the better off you are; and the easier it is to have the stuff you need to play it, likewise.
- Something cool SW:CCG and L5R have done is build the dice into their cards. Almost every card has a "Destiny" value (Star Wars) or "Focus" value (L5R), and during any circumstances where skill, chance and circumstance should help decide the outcome of an event (Sword Fights, aiming torpedoes at the Death Star, contests of wills), each player drew the top card of their deck and added the value to whatever totals they were already counting. Star Wars took this an extra step and made a card's Destiny value roughly inverse to its Power Levels. Underdogs Never Lose in that galaxy far, far away, because The Force is with them; by enforcing this trope, Decipher not only added flavor but helped newer players (with weaker cards) compete against people who had sunk more money into their decks.
- Alternatively, consider marketing a smartphone app along with your cards. There are very simple iPhone apps that allow you to keep track of your life totals in Magic, for instance. This only obsoletes one of the several things a Magic player needs (+1/+1 or -1/-1 ccounters; creature tokens; etc), but it's a start.
- Target Demographic. The Pokemon CCG is so simple it's almost "solved"... but that appeals to its under-10 audience. The Star Wars CCG had Loads and Loads of Rules and was Nintendo Hard, to the point that even experienced Magic players could get fumbled up. You want your game to have depth, which is difficult to achieve and even more difficult to describe, but it has to do with how its mechanics interact—or, rather, whether they do at all. A game with "depth" is typically described as "Easy to learn, hard to master," and that's the sweet spot you want, but what counts as "easy to learn hard to master" will change depending on the intelligence level of your players. Adjust accordingly.
- This is also important from a psychological angle. Simply put, every person who plays the game is going to invest a certain amount of time and money into your product, and they want to feel like that investment wasn't wasted. It's called the Sunk Cost Fallacy and it's definitely something you can exploit to retain players, but only if the game is fun enough to hook them in the first place. (And let's not talk about Quality by Popular Vote; it's another thing you want to exploit, but popularity and Hype Backlash go hand in hand because someone will always dislike your game, even if it is genuinely, legitimately good.) So it needs to be not just fun, but relatively easy to pick up... and with enough depth that the player feels like s/he is learning and improving. The more time, effort and money you can get your players to invest in your product, the happier they are and the more loyal they are. Exploit this.
- Variable Player Goals. As mentioned, you need them, if for no other reason than that it allows Comeback Mechanics. But that means you need to decide what they are. And, unfortunately, the sky's the limit, since CCGs can take place in any milieu and focus on any scope, from one-on-one fistfights to games of thrones to saving the galaxy from evil.
- One critical thing to think about is whether it ought to be possible to have non-violent win conditions. Almost every CCG involves defeating your opponent in direct combat; but some, like L5R and some of the Golden Snitches in Magic, allow you to simply turtle up, defend, and win by meeting some sort of passive goal.
- Geo Effects. Magic and Pokemon do not feature any sort of terrain; duels just take place in some vacuum somewhere. In comparison, the Star Trek and Star Wars card games both involved geography—you had to travel back and forth between different locations to accomplish varous goals. These games, not coincidentally, required much more physical space to play, and additional rules to govern movement. Having said that, Tropes Are Not Bad: additional rules means additional Loophole Abuse, and let's face it: Loophole Abuse is one of the foundations of strategy. (Tactical Rock–Paper–Scissors consists of nothing but!)
- Card Draw Rate: Magic only lets you draw one card per turn. This can make it a very slow game, and increases the importance of deck-building and deck optimization. Games where you can draw more cards are faster, and potentially more fun, because everyone has more options, but also means that a skilled player can run away with the game more swiftly since s/he is more rapidly handed the tools they need to do so. Finally, this has an impact on the power of cards that themselves say, "Draw more cards." In Magic, the color that has the most card-drawing spells, Blue, is considered overpowered because of it; in Star Wars, where converting extra Force points into card draws is a normal part of gameplay (and there are some cards that let you convert them back!), such abilities are less remarkable.
- Discard Piles: SW:CCG had two discard piles. The "Lost" pile was where dead characters and the like went; but the "Used" Pile was where spent Force cards and some spells went. The Used Pile can be added back to the bottom of your draw deck at any time... meaning that some spells would come back again later. This was used as a form of Necessary Drawback: some powerful spells automatically went to the Lost Pile after use. A few were modal: they had an effect that resulted in being Used and another that resulted in being Lost. The point is that a card does not have to be one-use-only, and that there is plenty of design space to explore here.
- Luck Manipulation Mechanic: remember that stuff up above about drawing Destiny? A card used as a Destiny draw is put into the Used Pile. This means you can "stack your deck" by cycling through it fast enough that a desirable Destiny draw gets back to the top before the next time you need it.
- Character Development: SW:CCG, ST:CCG (2E), L5R and even Magic have all done this: release multiple versions of a character (a Planeswalker in Magic's case) which have different skills and are suited for different purposes. Typically the way this is done is to have a rule that you may only have one card of that character's name in play at a time, but then give each version sort of subtitle (James T. Kirk, Highly-Decorated Captain vs James T. Kirk, Living Legend, at complete random). In most games you may replace an in-play version with a different one, possibly at reduced deployment costs, but what happens to the first version ([[Permanently Missable Content lost for good? Back to hand?) depends from game to game (note also in this case that the "one in play at a time" rule is indicated by the dot before the name—ST:CCG allows multiples of Red Shirt-level cards). Pokémon also built this into play by allowing you to evolve your mons, but that's a different mechanic.
- Some card games require you to have a certain specific card before you can play: L5R requires you to have a "Stronghold" card, for instance, representing your chosen Clan. If you're going to do this, then for the love of god, make the required card Common. Hell, make them more-than-common the way Lands are in M:tG, or print them on the back of the deck box (L5R). This does not preclude you from printing actual-card versions of the card, or from printing more-powerful rare versions; it's simply to say that if one specific card is going to be necessary, then you had better make it easy for players to get their hands on. The opposite—having only rare versions of the required card—is called Fake Difficulty. It will reduce your revenue to zero, and you will deserve it.
- Card Frames: The "card frame" is, if you will, the game's Viewer-Friendly Interface: it organizes the data on the card so that players can easily scan that card and figure out what it does. For example, Magic always has mana icons in the top right, the card type right under the picture, and a panel describing the card's use occupying the whole bottom half of the card. The point we are trying to make here is not, "You should have a card frame design," though obviously you should; the point we are trying to make is, Consider having different card frames under different circumstances. In Magic, the differences are usually in color and texture (green cards look like they're made of lizard skin, while red cards are made of sandstone), but you could potentially have completely different card layouts for different circumstances; SW:CCG had Location cards that operated in both Portrait orientation (planets) and Landscape orientation (spots on that planet; Tatooine would be a portrait, Mos Eisley a landscape), and neither of them looked anything like their Character cards. This raises the difficulty barrier at entry—the player has to learn to recognize multiple frames—but speeds gameplay for experts, who can tell even more quickly what a card does.
SettingAs mentioned, most CCGs are adaptations of existing franchises. The reason for this is simple: it is quite difficult for a CCG to tell a story. If you decide to print the content on the cards themselves as flavor text, well, there's no guarantee any given player will see every card in the set, since some of them are rare and he needs to buy X booster packs to have a chance of getting every rare in the set, where X is the number of rares. If each booster is $3, you've just asked him to spend a crapton of money on a story. One that probably won't be very good, because just how much space is there on that little piece of cardboard. Alternatively, put the story in a Novelization... but then don't expect too many people to read it.
So the reason to adapt an existing franchise is also simple: it already has a story, known characters, emotional connections to and from the player. If you see a card for "Bob the Clueless Troper", you may see a muscular middle age man with Badass Mustache and know a little bit about his personality (Macho Camp) from the card art , but you don't necessarily know anything about him beyond that. If you see a card of "Josef Stalin" though, you have knowledge about him that predates the arrival of the card, and you know what it means if you manage to get Vladimir Lenin in play alongside him, or what might happen if he has to fight against your opponent's Adolf Hitler card. Even better, you might be excited for the chance to pit him against the card of someone he never faced in-person, like Barack Obama or Osama bin Laden. Oh, and as an added bonus, you can withhold popular cards for later expansions. Players will whine and gripe and complain... but if you tell them that the long-awaited Theodore Roosevelt card is finally seeing release in the next expansion, they will line up and they will shell out their money.
It's hard to tell a story using cards... but that doesn't mean it's impossible. And, since almost no one has ever tried to do it, this design space is ripe for mining. If you can come up with a way to incorporate story into gameplay—to construct a narrative using the cards themselves—you might seriously, seriously be on to something. One obvious solution is to set up combos somehow: Card X can only be played if conditions A, B and C were already fulfilled. This would play into a modified "twilight pool" mechanic, where added points had certain qualities ("Sword of Plot Advancement may only be played on an Equipment card that was already played this turn, and if you have killed at least one enemy character this turn"); or maybe Card X needs to be played at the beginning of the turn, which gives the opponent a chance to stop it. The point is, each card becomes a modular piece in a story and can be assembled at will. See also Tabletop's Let's Play of "Gloom" for an example of how the cards can be used to inspire storytelling: in Gloom, an "event" card is combined with a character and the players get to make up their own explanations for what exactly happened. (Of course, this is totally optional, and the game can easily be played without all this insipid characterization.)
Another thing that Warhammer 40K and L5R both did was allow the results of tournaments or normal gameplay to determine the metaplot. WH40K used to run "global campaigns," providing Back Story and then allowing players to submit the results of matches in support of that back story. Games Workshop then tallied all the results they received and eventually declared who had won the Thirteenth Black Crusade (Abaddon has Cadia, but he's cut off from the Eye of Terror and any reinforcements by the Imperial Navy). And at one point a Shadowlands player came within a hair of taking the world L5R championship, which would have had very interesting implications for the game's future. (An expansion taking place After the End was released, though with an "Elseworlds" flavor to indicate it was non-canon.) This is not the same as building a story out of each individual match, but it's something to think on.
Another nice advantage about starting your own Intellectual Property is the ability to avoid CCG Importance Dissonance, something that both the LotR CCG and the Middle-Earth CCG before it fell serious prey to. Not only do you not have to create filler cards out of Extra Of The Week #13, you aren't bound to that model by the franchise's existing story. Most stories have these things called Main Characters who appear in almost every instalment of the series; these cards will be—are required by the Fan Dumb to be—the most powerful cards in the game. If "Third Orc From The Left" is able to take on Frodo and win, fans will scream that the game is ruined... even though the same thing results if you let Frodo hand out Curb Stomp Battles (which would not only make him a Game-Breaker but is Canon Defilement!). This is where that whole Variable Player Goals thing can come in handy. Frodo does not and has never had the combat chops to win a Multi-Mook Meleenote , but he is also the Ring-bearer and is gifted with some level of Incorruptible Pure Pureness. Give him extra resistance to the Ring's temptation mechanic and suddenly he doesn't look so useless.
RulesAs previously mentioned, you'll want to balance the game's difficulty very carefully. You want it to be easy enough to be accessible, but with enough depth to really suck people in. One of the simplest ways to do this is to make some of the rules only matter in certain situations. For instance, one of the rules of Magic is that if you ever have to draw a card from your deck, but can't (IE you're out of deck), you lose. Because it takes more than 50 turns to get to this point in the normal course of things, most beginning players can safely ignore this rule. Eventually, however, it'll crop up... and probably in such a surprising fashion ("Wait, I can lose to that? Let me get the instruction manual.") that they'll never forget it, and then later try to design a strategy that allows them to "deck" their opponent as they themselves were decked. ST:2E actually has little notes in its instruction manual: "Text in these boxes should be ignored if you're reading this booklet for the first time. After you've played a few games, come back and read the manual again, this time with the boxes. Then you'll be able to pick up some of the nuances." Your whole game can be designed like this. Have as many rules as you want... but make as many of them optional as possible, so that the game can be played using a bare minimum of them.
Power Creep is a result of a game whose rules are too limited; there's only one thing you can do and only one way to win. SW:CCG, Pokemon and Yu-gi-oh are all subject to this. So Variable Player Goals and alternate win conditions stop looking like optional features and more like absolute necessities, because they can help you avoid Power Creep, a thing that is dangerous to the overall health of your game. It led Magic players to coin the term "strictly better," for when two cards are identical in all aspects except one, and in that one aspect, one of them is, well, better. Shock vs Lightning Bolt is perhaps the iconic example: they're both Instants that cost one red mana, but while the first spell deals 2 damage, the second deals 3, giving you 50% more bzzt for your buck. This kind of power ramping is dangerous because, the moment you publish "Lightning Bolt", every "Shock" card on the planet is suddenly worthless... and the last thing you want to tell your consumers is that some of the product they shelled out money for is now without value. The potential for ragequits is alarmingly high. Even better, with multiple power scales, you can strengthen a certain aspect of the game and then deliberately weaken all others on an expansion-pack-by-expansion-pack basis. This not only slows down Power Creep, but it encourages people to — guess what — buy more cards, since they'll inevitably want the strongest everything... and they can't get it in the same place.
The opposite, rules that are not specific enough, encourages you to just keep developing "Complexity Creep"—New Rules as the Plot Demands, which is just as bad. ST:CCG is the banner example here. At the beginning of First Edition, it had eight card typesnote , but each new expansion introduced some new gameplay mechanic, and by the end, it had seventeen. This created a huge barrier to entry; new players would go up against decks that were doing things which were, as far as they were concerned, Beyond the Impossible, and which they (the new players) had no hope of replicating. Not to mention that learning tons of rules is time-consuming. Decipher learned their lesson: Second Edition launched with only seven card types and remained that way forever. (By odd coincidence, its rulebook is also quite a bit shorter.) Complexity Creep is just as dangerous as Power Creep, and while both are inevitable, you want to keep them to a minimum.
So what do we do? Keep the new rules on individual cards. Many Magic cards actually break the game's rules ("'Shadow'? This creature can't be blocked in certain cases?"). And Rule Zero of Magic is, "If a card ever says it can break the rules, the card is right." But the end result is that the cards carry new rules with them. To aid this, cards meant for beginners will often have reminder text on them, explaining how they break the rules and what that means. This is still New Rules as the Plot Demands, but in a much more modular fashion. Magic also tends to keep real rule-breakers to rare or at least uncommon, limiting new players' exposure to them. But the point we're trying to make is to leave yourself space for new rules on cards, not in the rulebook. Ideally the rulebook should never have to change from the day of first printing to the day your game is finally canceled. (That's obviously impossible, but less impossible than you think.)
Another helpful weapon in this arena is "flavor," which has to do with how memorable the card's design is and whether it taps into some form of shorthand. In other words? Tropes. Tropes Are Tools and you should use them unabashedly in designing individual cards. If it say that a card called "Lightning Bolt" does three damage to whatever it hits, that makes perfect sense. Likewise, if the rules tell you that a monster with "Flying" can't be intercepted by creatures without it, you nod and go with it because of course a lion can't stop an eagle. Look for this kind of resonance. Use it to communicate concepts. Design cards around it. Be shamelessly troperiffic, because it will make individual cards easier to understand.
If you are going to have Variable Player Goals, you absolutely must have that ever-elusive quality "depth" in the sense that each goal needs to give you the capacity to interfere with a player who is trying to win the game some other way. And that made life difficult for the designer. But no matter which goal the player is pursuing, they must have some ways of competing towards the other ones, if only to defend themselves against others who are pursuing it. Either that or you must allow such efficiency of strategy that players can achieve their goals in very short periods of time. During some of the early days of Magic there were Red "Sligh" decks that could do the requisite 20 damage in four turns, for instance. During "Combo Winter" there were Tolarian Academy / Stroke of Genius decks that could win in three.note Such decks are Game-Breaker heaven, and the Expansion Pack that enabled Combo Winter actually resulted in Magic's entire Design & Development team getting called into the CEO's office and yelled at. (Red gets a bye because it's a Fragile Speedster: if those decks don't win by turn 4, they'll almost certainly run out of steam. And it's possible, if difficult, to survive a Red onslaught. The Combo Winter decks won on Turn 3, period, and the only way to defeat them was to also play a Combo Winter deck and be Player 1 instead of Player 2.) Long story short, you don't want your game to contain an environment where everything is decided in the first two minutes. So every player needs to have some capacity to fight every other player, regardless of how either of them is trying to win.
Legal PitfallsWizards of the Coast has issued a patent on the idea of turning a card ninety degrees to show that it has somehow been temporarily expended. A Cardgame of Thrones has gotten around this somehow, possibly because Fantasy Flight Games pays a royalty to Wizards; L5R uses "bowing" because Wizards used to publish that game. If you try to put a "tapping" mechanic in your game, Wizards can sue you, and they are a bit more likely to win than you are.
We've talked about the "Living Card Game" idea, which takes the "random" out of Randomly Drops. Your game could also be a "Card Battle Game," a digital (non-cardboard) product that doesn't have to be played in person. The Internet is a magical thing. A game that's programmed as a smartphone app, using Internet or even Bluetooth for interface, might be really wonderful. Alternately, if you equip every card with a QR code, your players can maintain a cardboard- and digital card library simultaneously, though obviously this verges on Copy Protection and will irritate some players in that way. This could also build into the aforementioned "storytelling via sequence of card plays" by having global results affect, for example, what cards you can even play. "Players of [X] faction have won #### duels in the last two weeks, and as such cards with [Y] symbol on them are now legal for play." The Internet and smartphones are at your beck and call; consider how you might integrate them into your experience.
Likewise, Wizards have started producing a tie-in Magic product called "Duels of the Planeswalkers." It's a computerized version of Magic... but it's not a Revenue-Enhancing Device (or at least not solely so), it's actually a gateway training product, giving players a chance to play a dumbed-down, single-player version of Magic, get hooked on it, and emerge into the multiplayer jungle of cardboard Magic already equipped with (most of) the training and knowledge they need to survive. This is brilliant marketing, and you should look for similar ways to get people involved in your game.
Most card games are not very funny. Why the heck not? SW:CCG in particular was written and designed with a clear eye towards humor, which players loved; though the real kicker is the card "Barber Pole" from ST:CCG, which said, literally, nothing but "Plays on table." As in, This is a permanent, put it on the table and leave it there. What did it do? Nothing. It was literally useless. It was a Junk Rare of the most blatant nature. But the mere fact that Decipher were willing to waste cardboard on it was a lot of fun.
Suggested Themes and Aesops
Set Designer / Location Scout
The GreatsWell, really, Magic: The Gathering. The only game that ever got close in terms of gameplay was the Star Wars Customizable Card Game. Pokémon and Yu-Gi-Oh! have their adherents, but they may not provide the gameplay inspiration you need.
The Epic FailsThere was a period in The '90s where game studios were throwing cards at any franchise and seeing what stuck. Most of them didn't.
Cautionary TalesHecatomb was a card game with few, but devoted adherents, designed by Wizards of the Coast. It had a number of similarities to Magic, but primarily diverged in two ways: first, players played maniacal villains who sought to destroy worlds to enhance their own power; second, up to five monsters could be combined into a larger "abomination," which augmented one monster with the powers and strength of the others. Because of this mechanic, the cards were five-sided and plastic so that clear edges could show the abilities of the monsters below. While innovative and fairly novel, this made cards a good deal more expensive to produce, and it was a somewhat common occurrence to open a pack and find one or more cards which were cracked and unplayable.
There are a number of mechanics that Magic has toned down to large extent. For instance, you're rarely asked to shuffle things into your deck anymore, and you're rarely asked to roll dice or flip coins in large quantities. Why? Because these activities are not fun in the context of a magical duel, which you had to hit Pause on in order to finish shuffling whatever-that-darn-thing-is into your deck.
Directed ReadingLevel One is a Magic: the Gathering strategy column written by Mike Flores. As implied by its name, it handles very basic strategy and strategic concepts, the building blocks of Magic. Not all of it may be applicable, but it'll give you food for thought.
Mark Rosewater writes one of the most comprehensive design columns on the Internet; game designers and would-be game designers from every genre and medium tune in every Monday to see his brilliance. And, since he's one of the lead designers of Magic, much of his advice is tailored to this genre. In particular, his articles "Ten Things Every Game Needs," Magic Design Seminar: Looking Within and When Cards Go Bad (Revisited) are so on-point that we could have just copy-pasted them here instead of all the original research we've done. But that would be plagiarism. And That's Terrible.
Extra Credits has only done a few videos on collectible games, but as usual they are astute and efficient. The first was a basic overview of the premise of collectability; the second catalogued the pitfalls inherent in the genre, and the third its strengths. They also have videos on topics that are not CCG specific, like Power Creep, fanbase management and more. On their sister channel Extra Play, James has done quite a few videos talking about the mechanics of the computer CCG Hearthstone.
And finally, play games. As many of them as possible. The more overview you have, the better, and the easier it is to steal from everybody instead of plagiarize from just one game. And stealing from everybody is called "research."