Alfred does not approve of nor participate in the Wayne tendency toward water battles on Wayne property (or, in truth, anywhere else) but two times a year he will tolerate them on the grounds that nothing is destroyed and all damage done to the manor is repaired by combatants. Fair weapons are water guns and balloons filled with water and water only. Modified weapons and balloons need to be approved by Alfred. No one has ever disobeyed this rule as the consequences would be, no doubt, dire.
Bruce and Damian have similar approaches. One water gun: as big as they can handle with the largest jet stream possible. Bruce does his best to avoid any attacks (although all his children have an unspoken pact to team up on him to some extent), and while Damian shares the same philosophy, he is more prone to reject the shadows and wage war on his opponents, relying on his size, agility, and knowledge of the manor to keep him from being hit.
Tim is a sniper. He'll find a good place to settle down and proceed to make as many headshots as possible. If discovered (very rare) he will abandon his post to hide in another place where he will resume sniping. He does not enjoy being soaked, nor the unavoidable analogies to a drenched kitten that come after.
No one has ever seen Cassandra, save for fleeting glimpses. In all their raging battles, she has been hit twice.
Jason carries two guns, as realistic as he can get them. Hand guns, of course, with streams small enough to hurt and fast enough to be very difficult to dodge. He will also present Alfred with a seemingly endless line, twice a year, of 'improved' water guns that Alfred will always turn down for being: nuclear powered, having automatic fire, containing assault drones, or firing plasma bolts.
Dick uses six guns. At once. Juggling. One for every participant, he says. If Alfred would only join, he would prove he could use seven, he says. Little guns with quick bursts, it is difficult for Dick Grayson to sustain fire and avoid being hit. Fortunately, he enjoys getting drenched. Some disreputable members of the household (Bruce Wayne) have gone so far as to accuse Dick of being a showoff!
