I'm at waukeens rest on the Druid rescue mission. Now I've got the Ranger with Wasteland Wanderer: Fire and the Ranger have taken a potion of Fire Resistance. which means I shouldn't be taking any damage at all from the fire but I'm taking damage like I've not taken the potion nor have the Wasteland wanderer: Fire. What is up with that there? After all, just with the fire resistance potion, I shouldn't be taking any damage but I'm dead in no time when I try to rescue that man that is trapped in there. What good is a "Fire Resistance" potion if it doesn't work? Better off leaving it out of the game.
No, that's not how resistance works, I'm afraid...
As I mentioned to you, DragonMaster69, the last time you posted this:
Resistance doesn't stack, and it doesn't measure percentages per se. You're either resistant, in which case you take half damage from the damage type, or you are not, in which case you take full (or potentially, you might be vulnerable, and take double but that's exceptionally rare). If your Ranger has fire resistance then she is taking half damage from all sources of fire already, and that's it. Unless you have something that will grant you immunity to fire damage, that's the best she can do - there is no such thing as double resistance.
You are taking damage as though you hadn't drunk the potion, because you are already fire resistant, and the potion has no further effect on you. You'd be better off giving it to someone who is not already resistant.