You have learned the deadly art of poison delivery, and can guage, roughly, how effective such an attack will be.
Prerequisites: Nongood alignment, Sneak Attack +4d6 or the Signature Style class feature or 3rd Favored Enemy.
Benefit: You never poison yourself when applying poison to a weapon. You may also attempt to read, roughly a target's Fortitude save against poison by spending a full-round action in observation within 30 ft. of your target. Every 5 ranks you have in a single Knowledge skill relevant to your target (for instance, Knowledge (dungeonerring) against aberrations) adds 30 ft. to this range. The possible results are on the following table.
| Target's Fortitude save bonus against poison | Your Reading |
| +3 or less | Weak |
| +4 to +9 | Healthy |
| +10 to +15 | Moderately strong |
| +16 to +21 | Strong |
| +22 or higher | Practically immune |





