Snowballs are stackable projectiles used in the 2013 Christmas Event. They were used to pelt Gublinchs and other players throughout the event. They may also be obtained by operating a reindeer hat and snow globe, obtained during Christmas events. Contrary to common belief, snowballs will not "melt" after Christmas events.
The snowball must be equipped in order to throw it at other players or Gublinchs. Normally, players can simply left click on other players to throw a snowball at them however in PVP areas and/or minigames (if possible to do so in the minigame) players must right click the other player and select "pelt".
When players throw a snowball or have a snowball thrown at them, the damaged in combat sound effect plays. This can cause afk players to become alert and believe they are being attacked.
Despite being equipped in the weapon slot, the snowball can be taken to Entrana because it doesn't boost any stats. Seemingly contradicting, snowballs can also be taken into Castle Wars and is not considered a non-weapon. If taken into the desert, snowballs will not melt (even when the player is without a waterskin).
If a player brings snowballs into a Castle Wars waiting for game lobby, they are able to throw snowballs at other players. You are unable to throw snowballs at other players inside the minigame, however.
It can be thrown at other players in the wilderness, however this will not cause damage. The snowballs "attack" is the same punch/kick as the character would attacking something completely unequipped, simply they are holding snowballs.
The easiest way to get a large amount snowballs is to wait until the yearly Christmas event because, due to the snow on the ground, you do not need to repetitively summon snow with the reindeer hat or Snow globe as you can simply click on a pile of snow and all that is required is for the player to keep themselves logged in.
As of the 2016 Christmas Event, piles of snow are now located in Falador Park throughout the event. A good strategy for collecting snowballs, much like splashing, is to get a Gardner to attack you, causing the player to be logged in for an extended period of time.
If a player is performing an emote or skillcape emote and is attacked with a snowball, the emote is interrupted and the player staggers as they would if they were hit in combat.
If a player is riding the magic carpet and is attacked with a snowball, a temporary graphics glitch occurs in which it appears the player on the carpet momentarily walks on the ground.
If a player is teleporting and is attacked with a snowball, the sound effect and snowball reach the target nonetheless. The snowball will completely reverse its direction of travel in order to hit a teleporting player.
If a player is standing in a building and closes the door while a snowball is thrown at them, the snowball and sound effect still reaches the player inside.
If a player "changes rooms" or enters a dungeon while a snowball is thrown at them, the snowball and sound effect still reaches the player "changing rooms."
If a player enters the castle wars waiting for game lobby as an imp/sheep/bunny, they are able to throw snowballs at other players if they enter the lobby with snowballs already equipped.
At the Duel Arena, players in the stands can throw snowballs at players in arena. Players in the arena can likewise throw snowballs at players in the stands. However, players in the stands can throw rotten tomatoes at players in the arena, whereas players in the arena cannot throw rotten tomatoes at players in the stands. Because of this, many players will bring snowballs with them into the arena to return fire from players throwing rotten tomatoes (or snowballs) at them from the stands. Players in the arena may also throw snowballs at other players in the arena (but not rotten tomatoes), and, being a projectile, can be thrown over the obstacle walls. Players in the arena often bring snowballs into the duel arena to fire at or return fire from other players snowballs or attacks. It is possible for a player in the arena to throw a snowball at a player standing near the hospital/bank area of the duel arena, a potential graphics glitch in that the player appears to throw a snowball through a wall.