KDice

kdice is a browser-based multiplayer strategy game based on Taro Ito's Dice Wars. kdice is programmed in Adobe Flash and AJAX by Ryan Dewsbury and was released in 2006. Gameplay in kdice is a simplified version of Risk with the primary goal of the game being to control every territory on the map.

Overview
kdice is a turn-based game for seven players. It is played on a number of predefined flat maps containing 28 to 31 territories. The goal of the game is to control every territory on the map, by conquering the territories held by the other players and maintaining control over them. Alternatively, the strongest player (the one with the most territories) will win if all of the weaker players surrender (flag).

Game Setup
At the start of a game, territories are randomly divided among the players and a random number of dice (representing armies) are stacked on each territory. A player is then randomly selected to go first. Players take turns to attack and hold neighbouring territories.

In order to alleviate concerns that starting last (7th) in the first round is a disadvantage, the 6th and 7th players to play receive a "one die bonus". These two players receive an extra die in their dice distributions, increasing slightly the probability that their territories will survive the first round of attacks.

Gameplay
To attack, a territory containing more than one die is selected, and a target, which must be an adjacent territory held by an opponent, is then selected. The game then rolls a number of dice equal to the sizes of the dice stacks on the two territories and compares the totals. If the attacking player has a higher total, he takes control of the territory under attack; all but one of the dice from the attacking territory are then moved to the defeated territory. Otherwise (if the attacker's total is equal to or less than the defender's), the attacker does not gain control and the number of dice in his stack is reduced to one. Players can attack multiple times per turn, limited only by the number of their dice remaining.

At the end of the turn, the player receives a number of dice equal to the largest number of contiguous territories he controls. These are added randomly throughout the player's territories. The maximum number of dice allowed on each territory is eight. Surplus dice (up to 32) are stored if all territories have 8 dice; the game uses these to restack the territories where possible.

In contrast to Risk and similar games, dice may not be moved between territories, so forethought and strategic play are required when deciding where to attack.

Dice Roll Probabilities
The following table gives the probability that an attack will succeed, given the number of dice on the attacking and defending territories. The probabilities are given as percentages to one decimal place.

Note that when the attacker and defender have the same number of dice the probability of a successful attack is always under 50%. This is because when both the attacker and defender roll the same total, the defender wins.

* These are approximations -- the only attacks with a true 100% success rate are 7 vs 1 and 8 vs 1, and even a 2 vs 8 attack has a  win % slightly higher than zero.

Ranking system
As of February 11, 2007, a new scoring system was put into place which also ranks users based on dominance throughout the game in addition to the rank position a player finished the game. Dominance is based on the average territory count the player had, recorded at the beginning of their turn, compared to the total number of turns elapsed. In order to eliminate favoritism to players who can spread themselves out early in the game due to large dice stack placements, dominance calculations come into play after the third round of a game has completed.

As of July 31, 2007, a new scoring system has begun to be tested using only points instead of ELO. This system has been implemented as of September 1, 2007.

Strategy and playing styles
The nature of kdice makes its strategy very different from that of other "war games". The two elements that factor most heavily into kdice are chance and psychology.

Chance
The random die rolls mean that there is not necessarily one right move for a given situation; rather there is a balance of risk vs. reward. It may be tempting to attack whenever the odds are in one's favor (and a successful attack will be useful), but the nature of probability means that while the odds may be in the attacker's favor for a given single attack, they may be against his winning every one. A failed attack may create an opportunity for the opponent to counterattack.

Psychology
This is the essence of the game, although strategies differ as to how the psychology is applied. Various tactics include negotiating alliances, playing one opponent against another, and securing a corner or edge of the map while deterring other players from attacking the secured position. Strategy involves attempting to maneuver the other players into acting the way the player intends them to. kdice has several psychological aspects, the formation of alliances, the prediction of attacks, and vendettas.

An alliance (or "truce") may be formed between two players, allowing them to focus their attacks elsewhere, perhaps on a common enemy. A counter-alliance may subsequently form between players excluded from the initial alliance.

Alliances are of some controversy in kdice: 1. Some players are ideologically opposed to alliances, preferring to win or lose a game by their own efforts alone. 2. Pre-game alliances (PGAs) are alliances formed before the start of a game. They are considered a form of cheating as they make gameplay unfair for the other players. 3. Game etiquette dictates certain conventions, occasionally disputed, that players are expected to observe, e.g. that players may not unilaterally attack an alliance partner without good reason.

The prediction of attacks, like alliances, is completely psychological. Opponents do not always act rationally, and attacks with a low probability of success can still succeed. The most predictable attacks are those which (if successful) join territories owned by the same player into a single bloc; eliminate a relatively large stack of dice on a player's borders; or secure a defensible position.

Vendettas are a common feature of the social interaction of kdice. Because profiles remain constant, a player may hold a grudge against another for any reason, and may preferentially attack that player even if circumstances recommend a more conservative strategy.

Surrender
There is some controversy over surrendering (flagging). Most players accept that flagging simply means that a player is indicating that they are happy for the game to end with all players receiving a final ranking and score as it stands at the moment in the game play that the player flagged. And by raising their flag, these players speed up the conclusion of the game - when all of the weaker players have flagged the game is terminated. The players with this opinion of the flag status will continue to play when it seems advantageous to them even if they have raised their flag, for example if another player attacks them and they are in danger of being reduced in rank. On the other hand, a minority of players believe that a player who has flagged deserves a special status and should not be attacked by the remaining players. This is a continuing point of contention in the game mainly because it is a matter of etiquette rather than something enforced by the game itself.

Notable features

 * In-depth statistics tracking
 * Player ranking
 * Player profiles
 * Friends system