There are a number of different methods used by various groups as means to judge which side has won or lost.
Methods of scoring
There are a variety of methods used to score water warfare games.  Common methods are noted below:
This is a rather subjective means usually done by eye. Water fight participants simple do rough approximations regarding the amount of their clothing has been soaked through versus how much dry surfaces remain. In the event all participants appear to be fully covered with water, sometimes participants opt to wring their clothing as further means to show how wet or dry they are. Winners are often declared upon consensus by the group;
More precise methods of determining the amount of relative wetness are also available. This usually amounts to a measurement of the size of a single or multiple spots of water on an individual's clothing or equipment as predetermined before a battle. This method of scoring, while obviously maleable is most often noted in its most popular form, the "fist sized splash" rule. In this way, a participant who has a "fist sized" splash of water on his/her clothing is "out" for a period of time specified earlier in the game. Variants on this method include using this as a "kill" which dictates a "respawn" either instantaneously or after a set period of time.
This method of judging a hit relies on the agreement and honesty between players as to what constitutes a direct vs. glancing water stream hit. Some groups employ the rule that a 'fist-sized' area should be dampened on an opponents clothing to be counted as a hit while others are more liberal, allowing almost any level of water contact (apart from simply mist) as counting as a hit. Depending on the type of game being played, a hit would count either as a point or may result in a player being temporarily eliminated from gameplay.
This method of scoring relies on some form of tag (either water soluble or colour changing when wet) to determine whether a hit or elimination is successful. This is a more objective means of determining points or soaks compared to the methods listed above. However, many argue that use of a tag is not necessarily accurate as tags tend to be small, only on one or two areas on a player's body, and can be much more easily covered/protected unfairly during a water fight, making it virtually impossible to score.
Water-collection device system
Some would ultimately prefer a device that could record or report the amount of water actually received by a player during a water fight. However, the problem is that this type of device is hard to find and few are willing to wear them. Presently, there is only one known company distributing such a device. Soaking level as recorded by such a device would arguably be the most objective and suitable method of scoring for a water war fight, but as this type of additional piece of equipment is hard to find, costs more (than simply estimating wetness), and is not particularly accepted by most water warriors, this means of scoring remains used by relatively few.
Popular game types
There are many popular game types for team-based and non-team-based games. Common ones are summarized below:
The most common, unorganized water fight; everyone fends for themselves and there are no particular rules apart from no intentional physical contact between players. In general, players are allowed as many refills as available and gameplay continues for as long as players are willing. There are no clear winners in a soakfest, though group consensus may declare an individual or group of players 'leaders' based on general ability to deliver more water onto others as opposed to receiving it themselves.
This is one of the most basic forms of organized water fights. Drawing upon paintball rules, the idea is that a single water stream hit counts as an elimination from the game. Games are played until there is only one person or one team remaining on the playing field. However, unlike paintball, there are some debates regarding how best to determine whether a hit has occurred (See: Methods of Scoring above).
Variation on OHK, but instead of player elimination, a point is awarded for a soak, but the soaked player continues to play shortly after.
Capture the flag
This is where you try to stay dry while soaking your opponents with water. The objective is to stay dry and get into enemy territory and to find the enemy flag. The first team to bring the enemy's flag back to their own territory wins.
This game works like the simple game of tag, but using soakers and stream hits to determine who is 'It'.
Water dispensing devices
The original water guns were made of metal and fashioned after actual firearms. These early pistols did not dispense much water, but would likely be used to taunt or annoy others. Modern water weapons are much more capable of delivering larger volumes of water over greater distances.
Hoses and sprinklers
Common water dispensing devices, but are considered unfair or for refilling use only in most organized games due to the 'unlimited' nature of their water supply.
Small rubber balloons similar to party balloons, though usually much smaller, that can be used to dispense relatively large amounts of water to a target. Coming in a wide range of varieties, including multicolored and grenade color, water balloons are filled with water, tied and dispensed to a target (usually by hand- see water balloon launchers below). When a balloon reaches a target, the balloon usually breaks, resulting in the water covering the target. Water balloons are useful in several ways that soakers cannot be used. First, they have a wide blast radius, so if multiple targets are fairly close together, all or most can be soaked with only a single balloon. Also, this allows them for use when a target is behind a barrier, because a balloon does not have to directly hit a target to soak them, like a stream of water from a soaker. Secondly, balloons can dispense a larger amount of water to a target faster than most common soakers, and a user doesn't need a bulky, hard plastic soaker to soak a target. Disadvantages of water balloons are that less water can be carried by one person without a bag, and soakage range is dependent on the thrower's arm (except for launchers). Also, water balloons take longer to fill up and tie than soakers, and are rather fragile (they can often break when being transported, resulting in a wet user, not a wet target). Also, if playing with teams, one team may, for example, get a fort and the other may get access to water balloons.