This rule is a directly ported rule from AD&D 4th ed. to our own house rules for PFSRD [Pathfinder] system. The reason for us adding this rule is to lessen the stat build strain on certain class builds that have higher total base requirements or needs in campaigns in which we run a lower point total for building attributes. The breakdown of this is as follows:
- To calculate your stat bonus to Fortitude, you will take the higher bonus between Constitution and Strength from your attributes.
- To calculate your stat bonus to Reflex, you will take the higher bonus between Dexterity and Intelligence from your attributes.
- To calculate your stat bonus to Willpower, you will take the higher bonus between Wisdom and Charisma from your attributes.
For a breakdown on the basic meaning of Saving Throws, here's a link to the PFSRD online glossary.