I was wondering if a belt of incredible dexterity and a cat grace potion can boost a character dexterity to + 8 or not.
Their are both enhancement bonus, aren't they? This means that they won't stack, am I right?
You are correct. They don't stack.
They don't but I feel like in that sense potions are almost useless. I don't use potions much and would much rather purchase the on going effect. I would definitely consider using them if they stacked. And I don't think that an extra +2 attack and damage ultimately makes the large-scale difference, but enough difference to sacrifice an action to drink it.
What are your thoughts on house ruling them to stack? Broken? Meh?
Potions are one-time effects that you use when you need a boost, such as a fighter needing an extra few points of WISDOM for whatever reason. Yes, he'll have a belt of strength providing a long-term boost to his core ability scores,.... but it's a lot cheaper to buy a potion for the one session out of ten where you need the emergency boost to your Will save.
In that regard, it's no difference from the golf bag of weapons the fighter carries around. There are times when you need a ghost touch reach weapon, times when you need a merciful bow, and times when you need an adamantine sledgehammer. But you can buy all three of those for the price of raising your primary +4 weapon to +4 ghost touch permanently.
They don't but I feel like in that sense potions are almost useless. I don't use potions much and would much rather purchase the on going effect. I would definitely consider using them if they stacked. And I don't think that an extra +2 attack and damage ultimately makes the large-scale difference, but enough difference to sacrifice an action to drink it.
What are your thoughts on house ruling them to stack? Broken? Meh?
Potions are extremely useful at lower levels when you can't afford ongoing items. You can also use potions for stats that aren't covered by the item or to raise an enhancement bonus from +2 to +4 (this works until you have a +4 Belt of Str/Dex/Con @ 64,000 gp).
Potions are awesome unless you a) always have a buff-dedicated caster in the party or b) only ever start play at 10th level or higher.
As far as whether to take the action to drink the potion vs full attack, that's situtational. Most of the time, taking a round out of combat to buff is not worth it. If you need to get past DR or you can't hit the beastie or need to get your con or dex up to survive the next few rounds, then it's probably a good idea. Usually you want to get buffs going the round before you engage, or anytime you're otherwise prevented from making a full attack (waiting for the flyer to come down to you, having to move from one fight to the next, etc.). Or you want someone else taking their actions to buff you while you continue to attack.