An interesting concept I've been batting around with SLUG is the possibility of having a “secondary gauge” that's related to one of your prime stats, and can dynamically go from 0 to that stat's value. The effect of such a gauge would depend on the stat, like so:
Strength --> “Bravery” gauge
Constitution --> “Poison” gauge
Dexterity --> “Speed” gauge
Intelligence --> “Sanity” gauge
Wisdom --> “Willpower” gauge
Charisma --> “Influence” gauge
Bravery and Willpower are already in the works for the upcoming “expansion pack” including the new classes Dark Mage and Paladin. It would be interesting to see how the others could be worked in, perhaps as part of the same expansion pack.