Tarjan Tokens are small little brass coins that can be found in toasters throughout Colorado in Wasteland 3. Don't sell them to merchants for the measly 10 dollars they offer! They are worth far, far more than that!

The tokens can be found throughout the game world, but always in toasters. Here is a list of what toasters, and where they can be found.

Ranger Headquarters:
Inside the Cafeteria.
Level 3 in Toaster Repair required.
(I think you can get this one a second time in the last part of the game, when the map for Ranger HQ changes. Required level 10 Toaster Repair, may be a bug.)

The Warrens (Bizzare):
Inside the diner kitchen.
Level 5 in Toaster Repair required.

Broadmoor Heights Survival Bunker:
Level 6 in Toaster Repair required.

Union Station Bunker:
Level 6 in Toaster Repair required.

That is good and all, what they are, and where they are, but what do they do?

Well, they can give you impressive stat boosts for a limited time, or they can give you permanent perks, which are not as powerful, but do persist for the whole game.

First you need to head to the Bizzare. There, you will find Quarex and his museum called the Cabinet of Curiosities. Inside, and near the back by the giant stone throne is the Tarjan machine, a sort of fortune telling device.

Each token can only be used once, so you get four chances in total. There is no restriction on how many times a single character can receive a buff, but they cannot overlap. I found that when one character received a permanent perk, none of the others could get it later, no matter how many times I reloaded a save, so make sure you choose wisely. If anyone has experienced this any differently, please let me know.

Here is a list of all the benefits I received from the machine, separated into permanent perks, and the long lasting buffs.

Perks:

Precognition:
Permanent +10% Evasion.

Fortune Cookie:
Permanent +15 Constitution.

Eye of Tarjan:
Cold Resistance +1% and +2 to Penetration.


Buffs:

Cunning of Tarjan:
Experience Bonus of +25% for 10800 seconds.

Lightning Strikes Twice:
The next 5 attacks this character makes will have 100% Critical Chance.

Magic Fingers:
Barter skill increased by +1 for 10800 seconds.

I save scummed a lot for the information in this guide, but that doesn't mean that the information is 100% correct. If you have any evidence or experience to the contrary, such as characters not able to receive the same perks, or anything else you think could be useful to add to this guide, please leave a comment!

Edit: Also, it seems as though some new tokens may have been added since this guide was released. If you remember where please let me know and I will add it to the list, and credit you.

Thanks for reading!