Barter Skill Mechanics?

[monsterhart]

Title pretty much says it all. What are the mechanics behind the barter skill? If you want to read more, you can read about my experience with this game below.

A while back (few years?) I got Fallout 1 as part of a big bundle with a bunch of newer games I had on my wishlist. First tried it 5-12 or so months ago (played FO3 first). Near the beginning I explored the map a bit and wasted about 100 game days but didn't realized it until a few real days later when I only had a couple game days left and couldn't even make it to anyplace without running out of time and didn't feel like starting from the beginning so I just quit.

On my first play through I designed my character like I usually do in games, a big (usually but not always dumb) high Strength and Endurance type skilled with Melee Weapons, et cetera; a Fighter basically. In games where I can allocate my attributes I usually try to make myself the best in as many areas as possible and the worst in the rest, and if theres only a couple left I'll put it on one thing. It's more fun that way for me and it really doesn't matter what my stats are in any game that isn't horribly unbalanced.

Just started a new game yesterday and wanted to try something different, or the opposite as it turned out. I decided to balance his stats out a little more (but couldn't accept not being the best in at least one thing), and since Luck and Charisma are usually the first things I take all the points off of I decided to play a charming type and gave him Heroic Charisma, Very Good Endurance and Intelligence, Good Luck and Perception, Poor Strength, and with Small Frame - Bad Agility. Picked Barter, Speech, and Doctor for Tag Skills, and gave him Good Natured.

So my Barter was at 75% to start and I'm able to rip off pretty much everyone in Shady Sands leaving them with nothing but 1 or 2 caps, but I'm sure The Hub and such places will have serious merchants. Since tag skills go up 2% at a time, when I got my first level up I figured I may as well max it out, but it goes past 100% well before I spend all my skill points. So I need to know the mechanics behind it, so I don't waste skill points going higher than what's useful. The wiki, forums, and internet in general only say how starting skill is calculated and that it decreases cost to buy.

[BreakinBenny]

Barter works like this: your skill versus the NPC's one, if both are the same you two trade for the exact same value. If yours is higher then you sell for higher profit, while if theirs is you must instead give them more.

80% Barter vs. 90% means your stuff is 10% less valuable than their junk.

[monsterhart]

I've read in several places that sell value is set, and thus unaffected by Barter and that has held up in my experience. Purchase prices do go down though. It seems possible that you're right that its my Barter minus theirs for the percent cheaper (or higher if result is negative) than the sell value. My Barter is at 101% currently and with most people its about 50% cheaper to buy. The Hub merchant Mitch who I just looked up as having a Barter of 58% is a little over half the sell value to purchase back so that seems to add up. Does anyone know what the highest NPC Barter Skill in the game is?

[BreakinBenny]

The highest skill percentage in Fallout 1 is 200%, while FO2 notches it up to 300%... how curious.

[monsterhart]

Oh there is a max? I just guessed that it might go on forever. Idk if 200% would be any more useful than 199% or a lower percent though. If BreakinBenny is right then I can hypothesize that whatever 100%+Highest NPC Barter Skill is is the highest useful level but idk what the Highest NPC Barter Skill is.

[BreakinBenny]

Originally posted by monsterhart:

Oh there is a max? I just guessed that it might go on forever. Idk if 200% would be any more useful than 199% or a lower percent though. If BreakinBenny is right then I can hypothesize that whatever 100%+Highest NPC Barter Skill is is the highest useful level but idk what the Highest NPC Barter Skill is.

I can think of Zack in the Boneyard and Mitch at the Hub's All-N-One Store, their Barter skill is 58%.

[Spanky McPants]

Fallout 1 Barter Mechanics

The price offered when buying from a merchant is given by the formula:

 
merchant offer price 
  = (value of object) * (bartering factor)
  = (value of object) * 100 / MAX[adjusted Baster skill level, 10]
  = (value of object) * 100 / MAX[(player Barter skill level) - (merchant skill offset), 10]

rounded down to the nearest cap, where the

• "merchant offer price" is the price offered when the player attempts to buy something from a merchant
  
• "value of object" is the hardcoded value of the object, which, incidentually, is the same price that the player offers to the merchant when attempting to sell an object to the merchant
  
• "bartering factor" is the price markup the merchant applies to the value of the object
  
• "adjusted Barter skill level" is adjusted level of Barter of the player's Barter skill level offset by a 'secret' merchant-based skill value, labeled the "merchant skill offset"

Merchant Skill Offset

The "merchant skill offset" is a hardcoded 'secret' value assigned to an individual merchant. For example, the following merchants in The Hub have the following skill offsets:

merchant       | skill offset
---------------+-------------
Mrs. Stapleton |           20
Jake           |            0
Mitch          |          -30

This skill offset is ordered so that the most expensive merchant to buy from (ie. Miss Stapleton) has the highest value.

Example 1: Normal Pricing

When the player's Barter skill = 100, the vendors will offer a 100cap stimpak for the following prices:

• Mrs. Stapletion: 100 * 100 / (100 - 20) = 125caps
  
• Jake: 100 * 100 / (100 - 0) = 100caps
  
• Mitch: 100 * 100 / (100 + 30) = 76caps (rounded down)

Example 2: Maximum Pricing

Note that the "adjusted Barter skill level" never goes below 10, which means that the "merchant offer price" is "maxed out" at 10x the value of the object, no matter how low the player's Barter skill level is.

When the player's Barter skill = 20, the vendors will offer the same 100cap stimpak for the following prices:

• Mrs. Stapletion: 100 * 100 / 10 = 1000caps (maxed out)
  
• Jake: 100 * 100 / (20 - 0) = 500caps
  
• Mitch: 100 * 100 / (20 + 30) = 200caps (rounded down)

Appendix: Calculating a Merchant's Skill Offset

To determine a merchant's "skill offset" use the following equation, when:

1. the player's Barter skill is sufficiently high, and
   
2. by attempting to buy an object with a sufficient high value (generally 300caps or more)

merchant skill offset =
  (player Barter skill) - ((value of object) * 100 / (merchant sell price), rounded down)

The player's Barter skill is sufficiently high only when:

(merchant offer price) / (value of object) < 10

Otherwise, the player needs to raise their Barter skill level until the condition above is met.

The value of a sufficiently highly valued object is dependent on both the player Barter skill level and the merchant's skill offset (which may be unknown). Generally, an object valued at 300caps or higher is sufficient enough to calculate the merchant skill offset.

This condition is given by the following (complicated) equation:

  (value of object) > [(adjusted Barter skill level)^2 + (adjusted Barter skill level)] / 100

This condition can be met by an object worth 300caps even when the player's Barter skill level is 120 and the merchant skill offset is -50 (eg. Mitch), as follows:

  adjusted Barter skill level = MAX[120 - (-50) , 10] = MAX[170, 10] = 170
  (300) > [(170)^2 + (170)] / 100
    300 > [28,900 + 170] / 100
    300 > 29,070 / 100
    300 > 290.7

A lower Barter skill level (so long as it meets the previous sufficiently high Barter skill level condition) or a higher merchant skill offset (ie. a more expensive merchant) will reduce the value needed for a sufficiently highly valued object, with the lowest value being 2caps when the adjusted Barter skill level is just above 10.

  adjusted Barter skill level = MAX[10.0000001 , 10] = 10.00000001 ~ 10
  (2) > [(10)^2 + (10)] / 100
    2 > [100 + 10] / 100
    2 > 110 / 100
    2 > 1.1

EDIT: Updates to this can be found at following URL:
https://www.reddit.com/r/classicfallout/comments/d84pxt/fallout_1_barter_mechanics/