Dynamic Resource Costing and Strategy Selection
Many games involve the distribution of resources among players in a non-uniform manner. These resources may be special abilities that last either the course of the game or just a single turn; shares in different sorts of investments, consumable resources required for certain actions, or other possibilities. Ensuring that this distribution takes place equitably and that there is an element of strategy in the distribution process is commonly solved by means of drafting. Drafting describes a family of procedures where participants select resources from a common pool.
The simplest sort of draft is the finite draft, where there is a preset quantity of items available and known to all, and participants typically take turns choosing one item at a time for themselves until either the pool is exhausted or each participant has had some specific quantity of picks. The drafting of new players by professional sports teams in the United States, the selection of roles each turn in Puerto Rico, and the choosing of tiles during the parties in Traumfabrik are examples of such finite drafts.
Games often involve large pools of items or resources of which only a small fraction are in play at any given time. This is normally handled via a deck of cards that is substantially larger than the typical number of cards in play, however that is defined within the game. Passing out cards at random to players lacks any strategic choices other than how to deal with the cards one gets. Allowing players to draft from the entire deck is usually unsatisfactory as well, since such a profusion of choice is time-consuming and often leads to specific players always attempting similar strategies, since their preferred options are always available. The solution is to implement a rolling draft, where some fraction of the cards are available to be drawn at any given point, and as each one is chosen, it is replaced with another from the deck.
The simplest rolling draft employs a tableau of cards which have no special relation to each other, and when choosing one there is no consideration other than the relative values of each card to oneself and the other players. Union Pacific and Liberté both employ such a system for the cards one may draw each turn, with the added detail that one may also blindly choose the top card of the deck. (Effectively, one of the cards available for drafting is face-down, while the others are face-up.) The largest problem with rolling drafts that have no additional incentives is that of stagnation. Due to the nature of most games, certain cards will be of next to no value to players following certain strategies. If a card is not desired by any of the players, it will sit in the tableau for the rest of the game, reducing the choices available. Eventually, the tableau may become entirely clogged with such refuse.
A variety of extensions to rolling drafts have been invented to solve the stagnation issue. A typical one is the addition of discounts on cards which are indicated as undesirable due to having been in the tableau too long. Selecting a card from the tableau now has some extra cost, such as a payment in money or victory points, or an expenditure of action points for the turn. Cards enter the tableau at high cost, and their cost decreases each time they are not selected. Vinci and Lawless employ such systems for civilization abilities and cards, respectively. As shown by Vinci, costs may even be allowed to go negative, meaning a player is paid to take a bad choice.
Another means of avoiding stagnation is setting a limit on the amount of time a card can be in the tableau. This could take the means of a individual timer on each choice, whose exhaustion results in that card being replaced with a fresh one from the deck. Queen's Necklace combines such a countdown with diminishing costs, as described previously. Another elegant possibility is to order the choices into a queue. After each player's pick or after all players have had a pick, the oldest card is discarded, the remainder are shifted down, and new cards are added to the back of the queue.
Another complication that authors can introduce to a game is a draft where each choice is a collection of items rather than a single item. This means that players must now evaluate the potential value of each group, considering synergies and negative interactions between their constituent items. It can help keep the game fresh by preventing people from settling on accepted valuations for individual items, particularly if combinations of effects are highly situational in their utility or if some of the items in collections harm players and are to be actively avoided. While the piles could be generated randomly, handing the task to a human allows for the intentional setting up of difficult decisions, as in San Marco.
The use of drafting, similar to bidding, is an excellent means to help smooth out balance issues in a game. Allowing players to choose competitively what resources they get and how much they're willing to pay for them compensates for effects that are slightly overpowered or under-costed. (Effects that are completely out of line with others will still break the game, reducing it to the luck of who has the first chance to draft such a monstrosity.) On the other hand, this could lead to accusations that drafting is a tool for lazy game designers wishing to avoid extensive playtesting, but efficiency is a hallmark of genius.
Drafting is at its best in games that feature widely divergent strategy spaces, such that the value of a given resource to each player can be very different at any point in time. Playing well then becomes in part figuring out ways to effectively use items that can be drafted cheaply because they are of little value to other players. Additionally, drafting mechanics introduce the need to periodically make tough judgment calls as to whether one should select an item that is only of moderate to value to oneself primarily to deny it to someone else who could make great use of it. In multiplayer games there is the added tension of whether one should make such a move oneself or do something more advantageous and hope another player will block the opponent who could greatly benefit from that item.
Drafting also has some advantages over auctions as a way to dynamically price resources. Even on the first playing of a game, most players can determine which of several options is more advantageous to them at the moment, but determining exactly how much they'd be willing to pay for a specific option is harder. Auction-based games often take two or three playings before the participants come to a consensus about what sensible bids are, while draft-based games usually work out better on the first playing. This is not to say that drafts lack depth. Even though drafting is simpler than some other options, it is still an excellent way to achieve tense gameplay that allows the players substantial control over their strategy.
- Andres Santiago Perez-Bergquist