Noxious OT encourages PVP, when you reach level 80 you should be careful.
There is a Task from Death NPC (you must be level 150 or higher) that orders players to kill other players.
When killing a player, you gain some Stamina and a lot of experience, approximately 1k per level (e.g. level 200 = 2,000,000), up to a maximum of 4,000,000.
Luckily, as a victim, if you have your Blessings then there's little to worry about when dying except for loosing a few crystal coins and some experience.
Don't panic, keep moving randomly towards a Protection Zone and avoid at all costs being blocked (both by magic walls and by terrain). Do not waste your rune/spell turn in anything not fundamental. Be ready to use utani hur in case you get paralyzed.
NoxiousOT doesn't give you a Yellow Skull when attacking a PK attacking you, this means you can counterattack while still being able to enter a Protection Zone.
When a PK starts attacking, adrenaline rushes into your body and makes you panic, your life depends on a few seconds so make it easy to react by keeping Healing spells/runes on single buttons (F1 instead of Control+Shift+F1).
Remember that every 1 second you can use BOTH a Rune/Spell AND a Mana/Health Fluid. Always carry Health Fluids for emergency situations like this. When the time comes, spam those two hotkeys like there's no tomorrow. And carry as many as you can, if you are a long way from a Protection Zone, it will be a matter of who runs out of runes first.
It is useful to have a hotkey to something that says something that might distract the PK like “dude its me!! :D stop lol”. This usually works better than a “please don't kill me”. Also, keeping it cool with the PK as if you have everything under control will sometimes make them leave to look for someone else.
Carry a chameleon rune with you, whenever you see a PK in the area, you can go up a level and transform into a random object, they won't see your name and you will look just like some random object. Choose an uninteresting or cheap object: a corpse, food, a bag, a gold coin (remember that with chameleon you will convert to just one unit), ammunition, etc.