Double posty bump!
I did some pondering, it really is simple (unless of course new complications arise).
It is a scoring/elimination game. The game ends when one team has been completely eliminated, and the team with more points wins.
Each 'hit' (again, help me define a hit) counts for a point. A player who has been hit must proceed to a respawning area, and from there count thirty seconds before re-entering play. Better respawning rules are needed. For small groups familliar with one another, an hono(u)r system could be used. Larger groups may need to use a hit indicator of some sort, such as a paper towel sash or a Soaker Tag (in which case it's not quite a 1 hit scores game).
When a player is soaked (modifying this site's definition, 90% of the visible shirt is covered in water. Count it to the last drop, of course
. It means backpack users need fewer hits to count as soaked), (s)he is eliminated from the game and must exit the playing area. A 'soak' counts for ten points (or however many seems reasonable). Larger games may need a referee to determine what counts as a soak.
Scorekeeping is done vocally, shouting out score updates as they happen, but again, a referee may be required in larger games/games that include the guy who starts yelling out random numbers to confuse people.
This means a few things. One is that it's possible to have your entire team be eliminated but still win. Another, the soak might solve Marauder's LaserTag problem from his thread, where outnumbered and adventurous teams tend to score far more than their opponents. Putting that into a scenario, let's say you're outnumbered 5 to 1, you can realistically get 5 points, the other team can easily get 10.
There are still a number of problems, such as when do you stop shooting? Let's say you've got your WW Blazer ready and on the biggest nozzle (~8 second shot time I believe). You get an opponent, is it legal to hold the trigger down just to get them closer to 'soaked'? If two players shoot at almost the same time, one of them gets hit first while his/her stream is still in the air, by the time the second stream hits (assuming it's on target) does it count? Also, this still means a hit from an SS50 counts the same as a hit from a CPS1500
I guess a solution for the first two problems is to allow a post-hit duel period, so let's say for 5 seconds after a hit, both parties are permitted to shoot, but that does complicate things.