I probably shouldn't tell this story, but I'm only level 8 and it's worth the risk for 10kpp.
A friend and I, being veterans of EQ since 1999, and bored with POP that had just come out, we ventured out to start hacking EQ.
We found that it (was) possible to prevent the EQ client from consuming the ammo when thrown/shot etc. So, we made a berserker, and got one of those thrown weapons that has 0 delay. (I forget the name of the item, but it is really rare or lore or something, so they're not overpowered in live)
Since we had 0 delay, we could throw as rapidly as we could send packets to the server.
We programmed our own /throw command with a parameter for how many times we wanted to throw. We made it so that we could queue it up, too by targeting mobs one at a time and executing the command. Kiting 20 mobs at once in Plane of Nightmare? No sweat.
So, the story is: We could solo just about anything that couldn't kill us in two hits. It didn't matter if it summoned. See screenshots in the link below. Terris Thule was our biggest accomplishment in cheating, but we also solo'd Yelinak, Overking, WW dragons, Zlandicar, etc. Note: On the Terris-Thule screenshot, you don't see the killing blow because we had to camp out to drop aggro from the approaching gargoyles.
Screenshots
Disclaimer: The exploit was fixed (unintentionally) by a separate patch. I don't have contact with him anymore and I personally don't do any sort of hacking as I don't have time (work full time programming). So, developers/moderators: don't suspect me of cheating in p99. I'm clean.
[You must be logged in to view images. Log in or Register.] Also, he gets almost all of the credit as the programmer at that time. I was just an idea generator.