Speech

Speech is a Fallout, Fallout 2, Fallout 3 and Fallout: New Vegas skill.

In Van Buren, it was divided into two skills - Persuasion and Deception.

The ability to communicate in a practical and efficient manner. The skill of convincing others that your position is correct. The ability to lie and not get caught.

Fallout and Fallout 2
Initial Level: Starting Speech skill is equal to 25% + (2% x Charisma). Average characters will have a 35% skill.

Speech skill was in the first draft of Fallout Tactics skills, but was eventually left out.

Fallout 3
During dialog with characters, you may be presented with a Speech Challenge. A Speech Challenge is a response preceded by the word "[Speech XXX%]", XXX being the percentage chance of success (e.g., [Speech 25%]). Speech Challenges open up additional possibilities in dialog with characters, such as getting them to reveal information they would otherwise keep hidden or pay larger sums of caps for a task. Not every Speech Challenge will have the same chance of success, since some characters may be harder to persuade than others. If failed, a Speech Challenge cannot be repeated.

The percentage of success is determined by various factors. The primary factor is your Speech skill. The higher it is, the better the chance of success. Your base Speech skill is 2 * Charisma. Charisma itself also has an affect on your percentage of success. A character with a 1 in Charisma and 100 in Speech will be less effective than one with a 10 in Charisma and a similar Speech level. Having a weapon drawn will have a slight effect on your possibility of success. Finally, succeeding in a Speech Challenge with a character will make future Speech Challenges with that character easier to pass, if applicable.

Certain Speech Challenges are not checked against your Speech skill, but against other factors. These can include your S.P.E.C.I.A.L. statistics, certain perks (Lady Killer/Black Widow, Child at Heart, etc.), or your Karma. In these cases, "[Speech]" will be replaced with the relevant item being checked against ([Strength], [Karma], [Toughness], etc.). Such checks will occasionally override normal Speech Challenges. Note that these options, unlike a Speech check, will automatically succeed since you have met the requirement. Karma is an exception, as being evil or good will influence the response.

Speech Success Chance
The precise chance of success appears to be Charisma Bonus * Speech Skill / Difficulty, where "difficulty" depends on the particular Speech Check, but not on game difficulty level. Thus, doubling your Speech skill doubles your chance of success, and Charisma gives a non-linear bonus according to this table:

Sample difficulties for early Speech Checks are 215 to convince Lucas Simms to increase your reward, 147 to convince Gob to give you information, and 111 to convince Jericho to talk to you. Thus a 5 Charisma, 50 Speech character has a 66 base ability, and has a 31%, 45%, and 60% chance with these checks respectively. Having a weapon raised increases the difficulty by about 10%, so with a weapon up the chances would be 28%, 41%, and 54%.

Lucas Simms is actually a fairly hard sell; few Speech Checks are harder than about 170. The hardest Speech Check in the game involves the AntAgonizer, and is about 420.

Improving your Speech Skill
In order to gain a 100 in the Speech skill, without directly putting skill points into it, it is necessary to only have a -32 to start with. 132 points can be obtained in game from items, perks, and quests.


 * +10 to your Speech skill can be earned as a possible reward from the quest Oasis. You must pass the Speech Check with Sapling Yew regarding what Harold is afraid of. At the end of the quest, assuming you don't burn him, you'll get Yew's Bear Charm which adds +10 points to your Speech skill.
 * +10 for the Speech Bobblehead.
 * +24 (48 with the Comprehension perk) by collecting all 24 Lying, Congressional Style books. Two have certain requirements. (one for getting the Love Machine Theme in the Tenpenny Tower Suite and one for taking the Contract Killer perk) (1 additional book can be obtained if you let the ghouls in by force, during the Tenpenny Quest, that makes 2 for that quest)
 * +15 for the Scoundrel perk. (+5 for each level, with 3 levels total.)
 * +1 (2 with the Comprehension perk) for the Paradise Lost book from Tulip in the Underworld.
 * +15 for the Tag! perk
 * +2 from Charisma bobblehead
 * +30 from the Impartial Mediation perk with Neutral Karma.

A best strategy to max out Speech while keeping to most points for other skills would be to get all the points possible from the books for approximately +48. Then get the 2 Bobbleheads for +12. This will give you +60. Your character most likely started with between 15 and 25. This gives a total of 75-85. If you want a 100, fill the rest in using normal points at a level up.

As an alternative to using precious perks to maximize this mostly useless skill (see saving strategy below), one can wear the Naughty Nightwear and Button's Wig clothing items for a +20 bonus. All together, without a single perk (Other than comprehension, which all characters should get), one can acquire +90, and with the minimum of 4 to begin, one can have 94 skill with no perks/skill/S.P.E.C.I.A.L. points invested.

Strategy
In addition to counting towards the Silver-Tongued Devil achievement, successful Speech Challenges in Fallout 3 can yield the player any number of benefits: they may be rewarded with a significant increase in caps for completing quests, keys or passwords, Karma, experience points, or even the chance to peacefully resolve some quests without the need for violence. However, a strong argument can still be made that -- due to how Speech Challenges are presented and implemented in the game -- the Speech skill itself is the least important in the game.

Unlike Barter (which will affect a great many transactions in the game), Speech skill will only affect specific dialogue options for the NPC's that present Speech Challenges in the game. Putting a large number of skill points into Speech -- or, even worse, selecting it as a Tag Skill -- assures that your character will be very, very adept with a fairly uncommonly occurring game mechanic.

Furthermore, whereas combat skills might increase your accuracy with a specific weapon, odds are very good that if you miss, you'll get another shot. Literally. With Speech Challenges, you only have one chance. Since even a high Speech skill will not guarantee success, if you're serious about succeeding in a Speech Challenge, you're probably going to be careful enough to save the game before rolling the dice anyway. Using this strategy, a higher Speech skill will only increase your probability of success, which translates to theoretically fewer game reloads until you succeed. Considering this, spending ten points to increase from a Speech of 30 to a Speech of 40 is likely to be completely unnoticeable in actual practice.

It is not difficult to save the game right before initiating dialogue with most NPC's in the game. In circumstances where an NPC will initiate conversations with you that can include Speech Challenges (such as Bryan Wilks, Lug-Nut, or Goalie Ledoux), these NPC's will only appear under predictable circumstances (nearing Grayditch, obtaining the Naughty Nightwear, or arriving at the Red Racer Factory); thus, saving the game just before encountering these NPC's will allow you to use the same strategy listed above.

For NPC's who can present multiple Speech Challenges -- such as Bryan Wilks or Vance -- it is possible to choose the option to stop speaking to them after succeeding in the first Speech Challenge, save the game, and then talk to them again to attempt the second Speech Challenge.

Despite all of this, putting points into Speech still can be a smart move. This would help cut down on time spent reloading saves after failed speech challenges.

What Others Think of You
What other people think of you will make a difference in your speech challenges.

For instance, speak with Dukov with a weapon drawn and you will be less likely to pass his speech check.

Cheat
There is a glitch where you can talk to Pappy in Big Town and keep performing the speech challenge over and over again; this will help you gain the achievement Silver-Tongued Devil and also net you unlimited experience. Note: You have to speak to Bittercup first. A similar (as yet unpatched) glitch occurs in Little Lamplight. When speaking to Knock Knock it is possible to repeatedly tell her that her joke is funny for essentially unlimited XP. (Ask about morale to start the tree that leads to the joke)
 * Note: This glitch is patched in the latest version of the game. 
 * Note:"On the Xbox 360 version of fallout 3 you can get rid of the patch by going to system settings, memory, pressing the Y button when choosing storage device then selecting clear system cache then when it tells you this will perform maintenance choose "Yes" and it will get rid of all patches on your Xbox. Be careful though as this may get rid of the DLC quests on your file."
 * Note: If you have downloaded any DLC, and you delete the patches, you will not be able to load a saved game until you have redownloaded all required DLC's. There will be no cost for redownloading something.