Snowball

Snowballs are situations that gain momentum over the course of time, analogously derived from a snowball rolling down a hill, picking up more snow and momentum as it rolls. "Snowballing" generally describes the act of using so called "Snowball items".

Snowball items
Snowball items are items that make a champion stronger over the course of time, unless that champion is killed on a regular basis. While granting only low stats by themselves, the items allow the champion to gain stacks of a certain effect which further increase stats (e.g. bonus ability power or attack damage). Each kill grants two of these stacks, while an assist grants one stack. They do not retroactively grant stacks, i.e. kills and assists gained before the item was bought will not grant any stacks. The stack cap for the current set of items is 20 stacks. Upon reaching that cap, an additional bonus is unlocked for as long as no stacks are lost. When the champion dies, they lose a third of their stacks, rounded down. The stacks are bound to the item, meaning that if you sell the item, the stacks will be lost. Buying the item again will not replenish the stacks.

The snowball items give a buff upon receiving one stack.

The snowball items and their buffs are:
 * - Leviathan Armor
 * - Soul Engourgement
 * - Blood Tribute

Cost efficiency
While snowball items grant comparably low base stats (especially compared to their gold prices), a fully stacked snowball item grants stats that exceed most other items in the game, let alone within their gold price range. , for example, grants only 20 ability power at the cost of 1235 gold if the champion has not collected any stacks yet. At 20 stacks, however, it grants a total of 180 ability power as well as 15% cooldown reduction, almost surpassing, which costs 3600 gold.

From a cost efficiency perspective, and  break even at 5 stacks, while  breaks even at 10 stacks. Therefore, is generally considered the worst snowball item.

Semi-snowball items
Since they use a similar stacking mechanic, the following items can be considered semi-snowball items: These items gain stacks for each minion, monster and champion kill and have a much higher stack cap. With, the champion will keep all stacks upon death, while with , that champion will lose only half of them. Due to this, has a much higher stack cap than. Compared to real snowball items, semi-snowball items are not as devastating when fully stacked, but can still generate a serious threat, especially when is coupled with.

Countering
As soon as you realise that an enemy champion is getting a snowball item, it is essential to keep them from gaining stacks and kill them as quickly and as often as possible; they should be your highest priority in fights. Keep in mind that each assist grants one stack as well, making team fights very attractive for snowballing champions. Also keep in mind that, after a snowballing champion is killed, assists will still grant them stacks even after death. This makes it considerable to sometimes kill them last in order to drain the most stacks from them. Since does not lose stacks, it can hardly be countered and will reach its stack cap eventually. However, you can delay it by denying the owner farm.