The function GetIsSkillSuccessful() would be the key function call in your script.
I assume you are working on a conversation option for a bluff check. So you need to write a "starting conditional" script, and apply it to a conversation option in you conversation editor in the "Actions Taken" tab.
Check out this tutorial on making a quest. Its got the pieces you need.
here is a rough example of the script. you'll want to change the skill and dc depending on the situation.
When you save these scripts use a name that says what it is such as: ck_bluff_15
int StartingConditional()
{
object pc = GetPCSpeaker();
int skill = SKILL_BLUFF; // this is a constant integer for the skill
// see: http://www.nwnlexicon.com/index.php?title=Skill
int skill_dc = 15;
return GetIsSkillSuccessful( pc, skill, skill_dc);
}
