Check the arithmetic and the verdict separately.

A deterministic calculator for our original micro-RPG fixture. This tool does not call an AI, roll dice, retrieve a rulebook, or measure a vendor.

Enter dice you already rolled. Natural 1 and 20 have no automatic effect in this fixture.

Method: choose the die, add skill, subtract the poison penalty once, then compare to the threshold. These are fictional rules, not a commercial game system.

Original methods and dated field observations: AI Campaign Journal rules test.