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

There are many quests that can only be solved-or that can be more easily solved-through Speech. This skill largely eliminates the need for Charisma, so long as you’re willing to invest points into it. Your ability to get alternative solutions to quests is priceless and frequent, and a character build that doesn’t include at least 80 points of Speech is really missing the point of a Fallout game. It’s not really a priority, however, if you’re fine with exploring and grinding for a few levels. If you want to get right into questing, however, you might want to fast-track this skill.