Hackable: An ADnD Skill System Inspired by Saving Throw Priority

I had a brainstorm for an alternative to Non-Weapon Proficiencies in ADnD 2E.

Every Class, except for Wizards use their Saving Throw for Spells for any Skill check they might need to make. Wizards use their Save for Paralyzation, Poison, or Death magic. 

If a character has an appropriate Non-Weapon Proficiency (NWP, hereafter), then every Class, except for Wizards, use their Saving Throw for Paralyzation, Poison, or Death Magic. Wizards us their Save for Spells.

Additional NWP ranks add a +1 to the die roll of the Skill check.

Thieves, Bards, and Rangers get to use their Percentile Skills in addition to making a Skill check. They roll their Percentile Skill first, if it succeeds, no Skill check is necessary. But if the Percentile Skill fails, they may then roll a Skill check.

This idea is based off of ADnD 2E's Saving Throw Priority.