what is backdooring
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. Another usage of the term Backdoor is when one or more champions push separate lanes whilst the rest of their team distracts or otherwise pressures the opposing team, preventing their recalls. Champions who can quickly push waves, such as Udyr, are commonly used in this form of backdooring.