Rogue is an assassin which relies on on stealth to get close to its prey. It can dish out an unexpected burst of damage, especially when hitting from behind. Its damage output spikes sharply during the mid game, so Rogue can snowball hard by getting a couple of early kills. For that reason, Rogue is often picked on low levels of play and it's common to see newbies cry for nerfs.
Despite all that, Rogue isn't viable in the pro scene and is considered a meme pick. The class heavily relies on stealth to be effective, but anybody can counter it with Stealth Wards. On top of that, its jungle clear becomes abysmal in the mid game, since it mostly relies on Smoke Bomb's AoE damage for clearing jungle camps. Smoke Bomb has decent base damage, but scales poorly, so its damage becomes almost irrelevant during the mid game. At that point, if the Rogue can't consistently score kills - it can't compete with other players and becomes irrelevant.
In the Novel
When Yuel's class was taught about Classmancers, many of his classmates noticed how effective Rogue was. As newbies, the kids struggled to deal with Rogue, so it became a strong and popular pick. However, Yuel quickly realized the class was weak and countered it with Stealth Wards, which helped his team win the 3v3 class competition.
|Backstabber||Passive: Rogue's basic attacks deal increased damage when they hit the target from behind.|
|Stealth||Rogue becomes invisible for a short duration. The stealth ends earlier if the Rogue attacks. Stealth duration increases with skill level.|
|Smoke Bomb||Throw a bomb which deals AoE damage and spreads smoke in the area. Enemies inside the smoke are robbed of their vision, whereas allies inside the smoke turn invisible. If Rogue walks into the smoke, Rogue gains invisibility for a short time, which persists even after Rouge leaves the smoke. The bomb's explosion has medium base damage, but the damage scales slowly with Attack Power.|
|Phantom Strike||Ultimate. Rogue blinks to a target location. If there's an enemy player there, Rogue strikes them for high damage. If the strike comes from behind, the target is also stunned.|