“The Speech skill governs how much you can influence someone through dialogue, and gain access to information they might otherwise not want to share.”

Speech allows you to interact with characters better. Any time a Speech option comes up, you’ll get a chance to radically alter the course of the conversation. Failure usually only deprives you of the benefit of suceeding-you rarely suffer penalties for trying. Success will convince NPCs to do things without a hassle, give you more money, or tell you about cool loot.

If you have a high Charisma, you might not need this skill, although there are few instances where Charisma actually comes up at all. Also, you get experience for successfully using Speech , unlike with having a high Charisma. You typically only get one shot at making a Speech check for an NPC about a specific subject, so save and reload if you fail. If you want to do quests off the bat, you should boost your Speech to get as much out of the quests as you can… a score of 50ish should minimize save/loading (although it’s by no means going to eliminate it). If you level first, you can put Speech off a bit. Saving and reloading will allow you to succeed at any Speech check… eventually, a higher Speech skill just cuts down on the bother. It’s good, but it can wait.