The exact level of poison inflicted by the spell depends on the magery and poisoning skill sum:
- Up to 130.0: Lesser poison
- Over 130.0: Regular poison
- Over 170.0: Greater poison
- Over or equal to 200.0: Deadly poison (with a 10% chance, otherwise greater poison)
If the target is more than 3 tiles away, for every tile over it, 10.0 points are subtracted from the skill sum. This is why deadly poison can never be inflicted from more than 3 tiles away.
This increased level of poison also applies to blade spirits you cast in the same way, except without a range check. If you have GM magery and GM poisoning, your blade spirits will also have a 10% chance of inflicting deadly poison, and otherwise inflict greater poison.