A while back when I played The Secret World I came across a piece of gear that transformed me into a cheater tho unintentionally. The helmet had a cool design and while its stats were pretty bad it had it had one special effect.
"Applying a heal over time effect on yourself or having a Heal over time effect tick has a X% chance to trigger a PBAoE (personal based area of effect) for X damage."
I always was a support or heal class player so naturally I tried to include this into my solo play where I usually had to switch to DPS or tanking builds. Without going into specifics TSW had a skill system that allowed you to "pick and choose" whatever skills you wanted while allowing you to use 8 at any given time. There are active heals or HoTs, passive ones triggering under specific conditions as well as tanking skills with a heal component. Through trial and error I loaded up on a combination that made me extremely tanky (high health pool and resists) while providing moderate healing capabilities (gear stats were dominantely tanky) and really bad damage output.....
...until I managed to get the PBAoE into play.
The "quirk" or rather "oversight" by the devs because it was such a mundane, low impact item was that the effect triggered without an internal cooldown. Minor right? Well I was able to pump out 3 HoTs actively and add 4 more through my passive skills. First test runs were disappointing mostly because I went against low lv enemies or small packs of equal lv opponents so fights were over too fast. The thing I discovered and eventually exploited was the fact that the game kept the stacks running if you dont go out of combat meaning I apply 5 triggers in my first fight and pull the next group while the last MoB still lives I enter the next fight with 5 triggers and can
continue to build up the counter and so on.
The result was a machinegun like Area of effect "death field" after a few fights which broke the game making the effect permanent until zone or logout. Gearing up in a tank set was the logical conclusion to survive massive MoB pulls.
It was glorious


Dungeon solo runs. Elite monster solo farms where I come across whole groups or raids and leave an empty area behind for them to cobble up the scraps. And my set-up was unique as well as unrecognizable. It was
mine alone and I was proud of it. Never perceived it as cheating but saw it as "clever mechanic usage". That being said I can honestly say that I never even "tried" to cheat I just used whatever stuff the game provided. And I also made a bug report when I figured out the game goes broke but nobody seemed to care.
Things changed when I incorperated this set-up into the rest of the game not just solo-play.
Dungeon runs (5 player count per group) where people laugh or belittle me because of my gear and skill selection and shut up quickly when I start to ramp up making runs a challenge to stay alive because the tank
cannot hold aggro and my damage numbers spike so much that even tried and tested "god-tier" DPS builds look like healer DPS numbers. Trash groups die so quickly that groups can simply walk from boss to boss where the challenge is to keep me alive because we dont have to worry about DPS anymore. Eventually I had dungeon groups running 3 healers, myself and one DPS or tank for crowd control and we blasted through content. Getting endgear items of course only intensified the issue. The set-up was of limited use in PvP but I also made it work there.
So I can only imagine the reports being made about me. I was accused of cheating directly but still...nothing changed. Some people identified the helmet as the culprit but even if you knew where to get it and looted it, you still had to figure out how to make it work. I had an advantage in this regard. Of course I had a lot of people chatting me up during that time fishing for information or asking for help. I taught friends and my guild how to use it and we had a lot of fun overall due to the unique gamestyle that was "ours".
Eventually the company crippled the helmet in apatch to a degree where it was unusable and became the novelty it probably was intended to be. I was a little disappointed by the overkill reaction rendering a large part of my own enjoyment worthless but at the same time was a little proud of making such a splash in the first place. No doubt people who I competed with for Mobs, drops or DPS saw me as a blatant cheater and tho the company saw an unintentional misuse or exploit so dramatic that they eventually opted to affect change I was never warned, never banned or penalized for this (maybe because I didnt abuse it to hurt others?)
So yeah, oftentimes we dont recognize that we are cheating or we justify it internally when we realize we are operating outside the games ruleset. I guess the thing that sets this apart from "griefing" is the intend behind it or how its applied.