I’ve always enjoyed the system used in Dark Souls games where you collect souls as a currency and can use souls to buy items, improve weapons, or level up. This

I’ve always enjoyed the system used in Dark Souls games where you collect souls as a currency and can use souls to buy items, improve weapons, or level up. This makes it so souls always carry value and makes it fun having to weigh the benefits of buying a desired item or leveling up. The game furthers the concept by making souls an attribute you always carry on you and can lose entirely when you die unless you recover them from your dead body before dying again. You can go from very wealthy to very poor quite quickly by trying to push a bit longer to obtain more souls to level up. Or you can cash out if you feel like the risk of continuing your adventure is too great. This concept combines well with reusable health potions that only refill after resting at the site where you can spend your souls.