Harassment (or Harass) is the act of constantly disturbing an enemy champion in lane while allowing them minimal chance to counter this (and punishing any attempts to do so). The harassing champion (harasser) receives minor advantages in the process which accumulate, granting early and midgame superiority.
Methods of Harassing
It is possible to harass enemy champions by using normal attacks or certain abilities. Thus, not all champions are potent of harassing effectively while others excel at it. The basic ways of harassing are:
- Zoning - using abilities to impede the enemy's positioning or to force him to either move to or retreat from a certain location. An easy example is Cassiopeia's Miasma.
- Debuffing - repeatedly applying crowd control to an enemy champion, occasionally combined with damaging spells or basic attacks for the duration, forcing him to retreat from combat.
- Kiting - by simply having a higher attack range, you can constantly land "free hits" on the enemy champion and just retreat each time they try to close up in order to counter-attack. This can be done with high range abilities as well.
- "Hit and Run" - melee-champions who feature abilities to quickly dive in and out of combat can harass by getting into range, landing a few basic attacks or abilities and then retreating before the enemy champion can react (such as Renekton's Slice and Dice or Lee Sin). This works best if you know that the enemy's abilities which would punish getting close to him are on cooldown.
The most common goal of harassing is to force the enemy to retreat or stay at a distance. This pushes the harassed player into an uncomfortable situation: either he or she stays away from the harasser, eventually losing minion kills, gold and experience, or if he or she tries to close up and is punished with debuffs, damage or even ends up being killed. While putting the harassed player under time-pressure (since, if harassed too long, he or she will be far inferior to other champions), harassing also demotivates the victim since he or she is hardly able to do anything about it on his or her own.
Since there are a variety of ways to harass, there is not one ultimate way to be safe against all kinds of harass. Trying to buy items that protect from the form of harrass you are facing is usually hard since killing minions to gain gold is being punished. The best ways to properly react is to either swap lanes with an allied champion who is not (or at least not as much) impeded by that form of harassment, or to ask your teammates for help and try to kill the harasser together.
Out sustaining your harasser is also a good tactic as some champions have a resource system like mana which will eventually run out. Early health regeneration, life steal, or spell vamp items will negate the effects of harassment.