If you have ever played DotA (the map) you will be familiar with the order ‘-test’, a mode which lets you try anything you want and practice your skills. League of Legends is going to have it too, but it is to be presented as a Practice Tool.
As described in a League of Legends post, Practice Tool is coming soon.
At its core, Practice Tool is a place where you can train your mechanics. It’s the training gym where you can go to brush up on your Lv1 last hitting, that early jungle gank route or your Riven mechanics. A simple, straight forward, single-player environment that lets you test out things like checking wall flash points or if you can solo dragon with a certain item build, without wasting hours in Custom Games. As League gains more and more similarities to a sport, it makes sense that there be a place where you can go to shoot hoops!
Rookies are always having hard time getting used to a new game and veterans are always bored when teaming with know-nothing game-toddlers. This practice mode provides a training place for rookies to get familiar with controls, skills and heroes, so that they can catch up quickly. Also, a team can use this mode to utilize new tactics with different heroes collocation. This mode is the one has been appealed for long enough, you can click here for details.