Misconception: League of Legends is a ripoff of Dota
Let's start with the creation of MOBA(Multiplayer Online Battle Arena) games and how it evolved to Dota/League of Legends.
Aeon of Strife
It all started with Aeon64's StarCraft map called "Aeon of Strife".
Valley of Dissent
Karukef innovated Aeon64's map by adding custom spells using Warcraft's World Editor and published it as a custom map in Warcraft Reign of Chaos.
Dota (Eul's era)
Eul, a Warcraft World Editor modder, decided to incorporate the ideas from the preceding games into a custom map in Warcraft Reign of Chaos called Dota. However, when Warcraft expanded to The Frozen Throne, he tried creating another Dota map called "Dota 2: Thirst for Gamma" as a sequel, however, it wasn't successful compared to the first Dota. Eul then mysteriously left Dota and left its code open source.
Dota Allstars
Meian and Ragn0r decided to combine the heroes from different Dota maps and created "Dota Allstars"
Dota (Guinsoo's era)
Guinsoo then modified Dota and balanced everything, including adding Roshan and alot of new features for competitive gameplay. With Guinsoo's Dota becoming a huge success, he recruited help from two modders named Neichus and IceFrog.
Dota (Neichus's era)
Guinsoo eventually left Dota (rumor has it that he got addicted to WoW). Neichus took over and did various balances and led the development of various Dota heroes today.
Dota (IceFrog's era)
Neichus also grew tired of Dota and left IceFrog as the head developer and the rest is history.
Okay now we've got that covered, we could say that Dota "DID NOT" start the MOBA genre. It was just a continuation of a previous game, same as League of Legends, so anybody who would say that League of Legends was a ripoff of Dota is horribly mistaken because Dota is also based off a game and League of Legends can theoretically be created WITHOUT Dota. LoL has the following features that a MOBA should have regardless of any MOBA game (just like in an rpg game, each player has a class/job to pursue).
1. A hero/champion to represent the player
2. A base to protect
3. Towers to help defend
4. Creeps/minions to additionally gain money
It is then up to the MOBA game to add features as they wish.