In BG2 this spell always was great, but I haven't seen any real uses for holy smite now(Im at the dragons eye 2nd floor) It doesn't work on lizards, nor on shadows:S(I thought those where evil!)

Is this spell only in low levels useless or does this so for the whole game?

It's not amazingly useful in IWD at the lower levels. I don't use it very often. Mostly I use it (with a paladin) for disrupting evil spellcasters or weakening groups of melee attackers clustered around my other tank. It's not that bad, though, if you aren't using evil characters. As it's an alignment-specific area spell, you could draw a group of evil creatures and weaken them all with one shot, not worrying about hurting your party.

I would guess that it doesn't work on shadows because they're not willingly evil (remember that the Priestess of Auril summoned and controlled them in the Vale and they were set free when you killed her). I suppose that reasoning could also be used regarding lizardmen, although it's a stretch (e.g. they are dominated by their king who is dominated by the Snake Goddess). Of course, if you're used to PnP D&D, that doesn't make sense. Evil should be evil, regardless of whether or not it is dominated by a stronger force.

The effectiveness of Holy Smite does go up with the levels of your character, so it does get somewhat better. Try casting it with a lvl 20 paladin and see how you like it... (although it may have an upper limit, I'm not sure)

One more thing - on the occasions where I use Holy Smite with a paladin I usually cast Detect Evil at some point on the creatures I anticipate casting HS on. That lets me know what creatures are considered "evil" and therefore will be susceptible to Holy Smite. All those free Detect Evil abilities of the paladin have to have a minor use somewhere.

I think that HS may also blind creatures for a short period of time.

Ok:)

Thank you(Y)

The spell description for Holy Smite says that it maxes out at 5d6 damage (at 10th level). That gives a damage range of 5-30. I suspect that limit is the same for clerics or paladins. It will also blind a creature failing its saving throw for one round.

Kind of a neat spell for clerical types because it is offensive in nature, alignment-specific and has a wide area of effect. The downside is the weak damage and short duration of the blinding effect. It's a free tool for the paladin, but I probably wouldn't memorize too many of these with a cleric, unless you have more than one and/or are trying to roleplay a cleric focused on offense.