Another good indicator is if the spell is an offensive spell and dosen't have a saving throw, such spell invariable require an attack roll, with magic missile being the obvious black sheep.
Most spell will say if a ranged or melee touch attack is required.
No, the spell states range of close and no mention of a ranged touch attack for the one target.
What Phasics was saying was "generally" spells with the details he/she mentioned will have touch/ranged touch rolls involved. The spell will say so in the spell description if so.
Generally any spell with a range of touch that the opponent will not wish to be hit by requires a touch attack. If they don't want to avoid the touch then it uses different rules.
Any spell which uses rays is a ranged touch attack. Anything else should be obvious in the spells description.
So Ill Omen from the Witch spell list would require a touch attack since it doesn't have a save? The reason I ask is because it's a pretty potent effect for a first level spell, but the spell doesn't say anything about it one way or the other.Another good indicator is if the spell is an offensive spell and dosen't have a saving throw, such spell invariable require an attack roll, with magic missile being the obvious black sheep.
Most spell will say if a ranged or melee touch attack is required.
It's not a potent effect, it forces them to reroll the next d20 roll they make, then the spell is discharged. at 5th level twice, at 10th 3 times at 15th 4 times and 20th 5 times. Considering that your average fighter attack routine is at least 5 attacks this effect would make him reroll each attack and the spell would be spent.
This is no where near as potent as the Misfortune Hex which does give a save but persists on ALL d20 rolls for the length of the Hex.
As to your question no Il Omen requires no attack roll and gives no save but its mind effecting which makes many creature types immune.
I figure anything that says 'touch' requires a melee touch attack, and I've kind of inferred that anything that targets based on a ray requires a ranged touch attack. Are there any other guidelines? Or am I off?
Pretty much got it down, though there are some spells that you don't have to roll at all for and the enemies just have to save against. Just read the spell descriptions and you'll do fine :D
actually a great use of Il Omen would be a swift Il Omen followed by either A Hex or Spell so they have to reroll their save and take the worse result