notes-games-deterministicFairCcg

In many CCGs (collectible card games) there is an influence from the external world in terms of the cards that each player brings to the game. How could we make this fair? Some ways:

• merge all cards brought by both players into the same pool, then this pool is copied and each player constructs a deck from one copy of this pool
• merge all cards brought by both players into the same pool, then use non-deterministic methods to deal from the merged pool into each player's pool
• merge all cards brought by both players into the same pool, then use non-deterministic methods to segment the merged pool into a number of groups divisible by the number of players; then assign the groups to the players such that each player has the same number of groups, then each player chooses a card from a group and then passes that group to the next player (with more than 2 players, the players sit in a circle and each player alternates passing to their left and to their right)
• like the previous, but with deterministic segmentation into groups; one way is to pass around the groups between the players, and at each step, each player chooses a card from the merged pool and adds it to the group they are currently holding (note that this building-the-groups phase precedes the phase in which anyone is drawing from the groups into their personal pool). Another way is for each player to be the 'builder' of a group; at each step each player chooses a card from the merged pool to go into the group they are building; when the group is 'full' it is put aside; groups built by one player could be first drawn from by that player, or by the player opposite, or nearly opposite, them in the seating arrangement.
• merge all cards brought by both players into the same pool, then the players take turns publicly choosing cards from this merged pool into 'their' pool, out of which they secretly build their deck
• merge all cards brought by both players into the same pool, then the players take turns publicly choosing cards from this merged pool into their OPPONENT'S pool, after which each person secretly builds their deck out of their pool
• merge all cards brought by both players into the same pool, then the players alternate take turns choosing cards from this merged pool to go into their pool, and choosing cards to go into their opponent's pool
• one player creates two, possibly non-equivalent, decks of cards. The other player then chooses who gets which deck
• each player brings a pool of cards. Each player then gets to swap some cards between pools, up to some limited number of swaps (50% of the pool?), with the rule that for every swap, the other player gets a swap. Cards once swapped can't be swapped back (this prevents the player who came in with the superior pool from simply using their swaps to swap back every card that was just swapped). Instead of or in addition to swaps, rounds of (a) removing and/or (b) taking cards could be used. After this, each player secretly constructs a deck from their pool.
• one player creates two, possibly non-equivalent, decks of cards, and assigns each deck to one player, and offers a 'bid' for a handicap for the other player. The other player (or all other potential players) then reply with an 'ask' for the handicap. When bid and ask cross, a match is made and play begins.
• have the two players play a number of rounds in each match, and switch decks between each round

In many of the above methods, a 'remove cards from merged pool' phase could precede the phase where a merged pool is divided into personal pools. This could allow all players a mechanism to 'veto' cards and sets of cards which are so complex that they fear that the player who brought the card may have some secret understanding of the cards' strategic implications. When any player chooses to veto a card, each other player then gets to veto a card, until no players wish to further veto. Note that some players may (ab?)use this to reduce all games that they participate in down to a well-understood game (eg only 3 cards per deck, all of which the player is familiar with), perhaps even a game that the veto-ing player has 'solved'. Provisions should be made for what happens if the pool is vetoed down to zero. Note that penalities or limits to prevent a player from vetoing the last few cards invites other players to show up with a deck consisting only of many repetitions of one very complex card that only they understand.

Note that in many of the above methods, 'deck' and 'pool' could be replaced by each other, and methods which talk about 'decks' could instead be used to create 'pools' from which each player subsequently secretly builds their own deck. Building decks after pools allows (a) skill in deck-building to be part of the game, and (b) potential surprise from the other player(s) about which cards from the pool were chosen for the final deck

Note that if we use a completely fair system, then there is no longer any need to rely on a central authority to certify that cards are not too powerful, and we can then allow completly custom cards ('proxy cards'/'constructed cards'). Note also that in this case, care must be taken to make sure that who goes first is also fair, because someone might bring a deck with only cards saying 'whoever plays this card wins'.

Also, how could we make the game deterministic? The basic non-determinism in most card games is card drawing, so instead let each player choose the next card to be drawn (either the same player who is 'drawing' the card, or their opponent).

• let each player sort their deck before each round within a match (so the player knows what they will draw, but not what their opponent will draw)
• let each player sort their OPPONENT'S deck before each round within a match (so the player knows what their opponent will draw, but not what they themselves will draw)
• each player sorts the even cards for themselves, and the odd cards for their opponent (or vice versa). In order to prevent the other player from deducing which cards have been added to the sort, this should be preceded by a method for dividing each deck into an 'even' and 'odd' subdeck. One methods is an alternating choice in which for each deck, the contents of the deck is made public and then each player takes turns choosing a card and adding it to the pile from which they will provided their sorted cards. Another method, which only reveals half of the deck to the opponent, is for each player to sort their own deck into even and odd subdecks, then they sort one of these subdecks and their opponent sorts the other; the opponent gets to choose whether they will sort the even or the odd subdeck, which prevents the player from putting all the cards they care about into the subdeck that they know they will sort.

Note that some of these methods force the complete or partial contents of each deck to become public.

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Some mechanics found in some CCGs:

• TURNS for each player
• PHASES of turns
• a limited or unlimited number of APs (action points) per turn that each player can spend to take PLAYER ACTIONS such as drawing cards, playing cards, or other things
• a DECK which is DRAWN from to make a HAND
• MULLIGAN: under certain conditions, some or all players may be given the option to veto the hand they have drawn and be dealt a new hand, perhaps with fewer cards
• a GLOBAL DISCARD pile
• a LOCAL DISCARD pile for each player
• SUITS; categories of cards
• rankings between cards, and/or between suits
• player HPs; the object of the game may be to reduce opponent HPs to zero
• player VICTORY POINTS; the object of the game may be to increase one's victory points to some fixed goal number
• player VICTORY POINTS; the object of the game may be to have the most victory points at the termination of the game
• CHIPS, which are similar to HPs or VICTORY points except that they may be transmitted between players voluntarily or as the result of bidding
• a single area of GLOBAL IN-PLAY cards (not associated with any particular player)
• an area for each player of OWNED IN-PLAY, persistant cards which are owned by that player
• ACTOR CARDS, which can take ACTIONS on turns, and which once played, are persistant
• a delay between when cards of some types may be placed in-play, and when they may be played
• actions that can TARGET opposing players
• actions that can TARGET in-play cards
• actor DPs (defence points)
• regeneration of actor DPs at the end of each turn
• actor APs (attack points; how much damage the actor does upon each attack)
• stereotypical ABILITIES of actor cards, some of which may have resource costs, some of which may cost APs, some of which may tap the card
• RESOURCE CARDS, which once played, are persistent, and can provide one or more resources of one or more RESOURCE TYPES anew upon each turn. These resources do not accumulate across turns (although resource cards are persistent).
• a limit on the number of RESOURCE CARDS which may be played per turn (usually 1)
• the freedom when constructing one's deck to add an arbitrary number of 'basic' resource cards, which are defined as cards which cost nothing to put into play and which do nothing except for provide one unit of resource of one specified type per turn (note that although the resource cards themselves do nothing except this, other cards may have effects triggered by the presence or usage of resource cards)
• TAPPING, or using some resource for one turn; 'tapped' cards are 'untapped' upon the conclusion of each turn
• arbitrary PLAY-ALTERING cards
• play-altering cards which affect all other cards which lie in certain (boolean logical predictates upon) categories
• persistant play-altering cards
• 'location modalities' which may be utilized only by certain actors; an actor which can attack via a given location modality can only be blocked by a card that can block via that same modality. The ability to access a location modality may be a permanent or transient ability
• 'instant' play-altering cards whose effect lasts only until the end of the turn, or until the sooner of some event, or the end of the turn
• cards which ATTACH to other cards which are 'in play' and alter the characteristics of those cards
• cards which attach to other cards may be killed when the parent card is killed, or may become UNATTACHED but lie in the owning player's owned in-play area waiting to be reattached
• an opportunity for opposing players to (sometimes) immediately RESPOND to a card played by the active player
• a LIFO stack of responses to cards (each card responding to the one beneath it)
• an opportunity for targeted players to (sometimes) BLOCK an action taken by a card
• various BATTLE mechanics for APs, actor DPs, blocking, and player HPs
  • one mechanic: attacker chooses attacking actor(s) from in-play cards, tapping them, and targets a defending player. Defender chooses blocking actor(s), (possibly tapping them, but possibly only until duration of the attacker's turn, instead of until the beginning of the defender's next turn). The AP of the attacking actor is compared to the DP of (defending actor(s); ordering by attacker's choice; or, defending actor(s); ordering by defender's choice; or, defending actor(s), ordering by some game rule; defending actors are KILLED until the sum of the DPs of dispatched actors is equal to the AP of the attacking actor(s), or until the AP of the attacking actor(s) is less than the DP of the next defending actor; if all defending actors are killed and there are still APs left, these may go to waste, or mby be applied to diminish the defending player's HP; if there are no defending actors, then the AP may be applied to diminish the defending player's HP). Various actor abilities and play-altering cards may alter this; eg an actor with the ability 'initiative' does not take damage from its opponent if it eliminates its opponent, unless the opponent also has initiative (extending this, 'initiative' might be an integer rather than a binary ability)
• an opportunity for targeted players to use in-play cards of certain types to block against cards, but only if the blocking cards have not been tapped in the targeted players' previous turn
• rounds of BIDDING
• a BOARD and an AVATAR upon the board for each player at a specified location (this may be thought of as taking the game out of the category of CCGs and making it a full-fledged BOARD GAME)

so, if we have a deterministic, fair, open CCG, where anyone can create cards, can we still have collectible cards? In this case, collectible cards do not make the game unfair, but they might add to the fun.

the blockchain can be used to record the ownership of cards.

but what gives cards value?

The blockchain, by recording the previous ownership of cards, can authenticate that a given card was created by a given entity, sort of like a 'signature' on a work of art that gives it value.

We could have the creation of each card have a 'cost' in terms of some underlying valued currency, like Bitcoin. But this doesn't support a card value over the 'creation cost' value (cards would not themselves act as a currency because they are not fungible).

A community of players who wants cards to be collectible could recognize the authority of one or more game balancing/card authorizing authorities. These authorities would only authorize certain cards for play. If they didn't like collectible cards they might authorize cards according to their properties, but if they like collectible cards, they might only authorize SPECIFIC INSTANCES of cards; ie if you clone an authorized card, your clone is not authorized, because it is an unauthorized instance. Again, the blockchain provides a lineage that keeps track of specific instances. So, anyone can create their own cards, but these new cards are not necessarily authorized by the authorities.

What would authorization mean for play? Well, some communities might want to ONLY play with authorized cards from a single authority. This, however, would prevent all play with self-created cards, as well as the simultaneous usage of cards authorized by multiple authorities.

Therefore, other communities might want to make rules such as, any card authorized by a recognized authority is ALWAYS accepted into play; other cards MIGHT be accepted, but might be able to be vetoed by the other players according to some veto procedure. This gives more value to authorized cards (any effort spent understanding the strategic import of an authorized card that you own is well-spent, since that card will never be vetoed if you introduce it into play), but still allows each player to create their own cards. This also improves gameplay by preventing other players from vetoing all but a handful of cards for which they have conclusively solved the strategy.

Of course, a player could be a member of more than one community, so in practice the meaning of authorized cards is context-dependent. I suggest that many players will sometimes play any-authorized-card-allowed, and at other times (especially in tournaments, although i imagine there will be both kinds of tournaments too) play only-authorized-card-allowed.

To get things started, the game software creator might want to set themself up as an authority and issue cards without any artwork or story text or interesting titles, just raw properties and utilitarian titles; encouraging competition from other authorities who provide more aesthetically pleasing cards.

Authorities can also delegate; for instance, the game software creator might run an authority that delegates to other card creators who are trusted to balance the game, provided they pay a fee. In fact, the software could support a special delegation mode that only delegates the right to change nonessential characteristics of existing cards, eg to take a card created by the parent authority and then add or re-do artwork, title, and story text. This allows an authority to delegate to an artist without trusting them for game balance.