Backdoor

Backdooring (also BDing or BD) is the commonly used term for a strategy whereupon one or more champions will attack the enemy team's structures such as turrets, inhibitors, or the Nexus without the support of their friendly minion wave. In other words, sneaking into the enemy base without having pushed the lane first.

Strategy
The benefit of the strategy lies in the element of surprise. Heroes have the opportunity to notice when a lane is being pushed and can move to defend it before the enemy reaches a turret, whereas backdooring can allow the turret to be destroyed before the defending team has a chance to react.

The term "backdooring" was originally coined by players of DotA.

Risks
Backdooring is generally seen as a high-risk high-reward tactic, as in order to attack the tower without friendly creeps nearby a hero must tank the tower's damage her/himself. There is also the danger of being alone deep within the enemy's territory, so the ability to escape in the event of being attacked is reduced. Turrets also take half damage from enemy heroes when there are no enemy creeps nearby, a mechanic specifically designed to make back dooring turret more difficult (inhibitors and the Nexus do not have this trait).

Countering
If a team expects their enemy to attempt a backdoor they will often leave one or more champions to ambush any would-be backdoorers. Doing this without a backdoorer, however, may hinder the team's efficiency in attack.

Champion Use
Os champions que podem telar são um bando de filhos da puta, Back Door é o caralho, porra de técnica de VIADO. Estratégia é o caralho, estratégia que é estratégia o cara pusha com MINIONS PORRA.

Reception
Backdooring is considered unsportsmanlike by many players and is usually frowned upon by casual players, some players actively "ban" the strategy when playing their own custom games. The majority of players, however, accept backdooring as being a legitimate strategy and there are no bans against it in matchmaking or ranked games.