How do I play Caravan?

The only way to get the Caravan Deck[fallout.fandom.com] is from Ringo[fallout.fandom.com] after completing Ghost Town Gunfight[fallout.fandom.com] (or killing him and looting it from his body, which is probably easier). These provide you with the minimum number of cards you need to play the game, but you can find other cards from vendors and merchants (2 caps per). Keep an eye out for 6's, 8's, 10's, and Kings (the strategy I'll describe later requires them).
Keep in mind that you can have multiple copies of the same card (i.e. multiple copies of the 6 of Spades).
If you have Dead Money[fallout.fandom.com] installed you can find some additional cards aswell.

I found I get the most cards from Lacey (the bartender)[fallout.fandom.com] at the Mojave Outpost[fallout.fandom.com] (anywhere from three to eight cards), go to her and buy the cards you need, then wait 3 days for her to restock and buy some more. There's a semi-rare bug where she'll sell a two copies of the exact same card, buying both will crash the game.

Taken from the Fallout Fandom Caravan card Page[fallout.fandom.com]

8 of Clubs
Sierra Madre Casino & Resort (Cantina Madrid)[fallout.fandom.com]: On the floor in front of a file cabinet to the right of the Cafe Madrid terminal and restaurant manager desk.

King of Clubs
Medical District[fallout.fandom.com]: Inside a 2nd floor room with an active electric hot plate, north of the Villa clinic and above a ground level cafe sign directly west across a courtyard from the room containing the 6 of Diamonds, on a round table in the northeast corner.

10 of Hearts
Villa[fallout.fandom.com]: Some distance north of the Villa police station and west of the room containing the 5 of Hearts, on the interior corner of a walkway to the southeast of a wall fountain. Going from the 5 of Hearts, out the door with a wall fountain, down the stairs, in the corner of the interior walkway on the left.

6 of Spades
Salida del Sol North[fallout.fandom.com]: In the northwest corner of a small courtyard with three bear traps and a dead tree, on the ground between a wall and three pipes, just west of the stairs leading to a room containing Dean's Secret Stash, a radio and two pool tables.

Taken from the FNV Fandom Wiki Caravan (Game) page

Cliff Briscoe - Dino Bite gift shop - Limited
Dale Barton - The Fort - Restricted
Dennis Crocker - NCR Embassy
Isaac - Gun Runners
Jake Erwin - NCR Embassy
Johnson Nash - Primm - Limited
Jules - North Vegas Square
Keith - Aerotech suite
Lacey - Mojave Outpost - Limited
Little Buster - Camp McCarran
Q.Master Mayes - Camp Forlorn Hope - Limited - Restricted
No-bark Noonan - Novac
Ringo - Goodsprings/Crimson Caravan Camp
Jed Masterson - Northern passage/Southern passage - Only available Honest Hearts[fallout.fandom.com]

Limited: You can only play with them five times and then never again
Restricted: You have to have good rep with their faction to play with them

Johnson Nash uses more face cards than any other player (more on what face cards do later), which can completely break this guide's strat. No-bark Noonan is the easiest to play against

After offering to play with someone, and after setting your bet, you'll be shown two long rows of cards. The top row is the deck you'll play with in the game, the bottom row is the cards you won't be using.

Use your arrow keys to move left and right, pressing W to add a card to your deck and A to remove it. Only select your 6's, 8's, 10's, and Kings. If these aren't enough to get you to the 30 card minimum add some Jacks and Queens. After that's done press F to play.

Although some of the game's controls are listed along the bottom right hand side of the screen, their descriptors can be a little vague or misleading.

Use your arrow keys to highlight a card in your available hand (these will be the five cards revealed to you in a fan)
Press W to select a card
Press Q to discard a card (this counts as your turn)
If you select a card and want to deselect it, press R. With no card selected, R is the forfeit button
E lets you choose one of your caravans and completely remove all the cards in it

When you select a card it will move to the left side of the screen. This is where the game is played. Use the arrow keys to place your selected card in one of the six sections available

Ace
Value of 1

Number Cards
Value of 2-10

You can play face cards on Caravans of the other player. They can do the same to you

Jack
When played on an Ace/Number Card, removes that card along with any card attached to it

Queen
When played on an Ace/Number Card, supposedly reverses the direction of hand and changes suit of the hand. I'm not sure if it's just my game being buggy, but Queen cards don't seem to do anything. I use Queens as null cards. If you know what they actually do I'll add a proper explanation here.

King
When played on an Ace/Number Card, doubles the value of that card. Multiple Kings can be attached to the same card, quadrupling the value

Joker
When played on an Ace, removes all other non-face cards of the ace's suit from the table (except that card)
When played on a Number Card, removes all other cards of that value from the table (except that card)
You can place multiple Jokers on the same card to remove any card of that suit/value placed after you placed your initial Joker

Just as a rule of measure for how weird this game is, we're only now getting to how to actually play the game ...

The aim of the game is to have the values of the bottom three sections (the caravans) be higher than their matching top three values. Keep your scores between 20 and 26 (any value outside of this is invalid). The game is won when no more moves can be made, and you have "won" more caravans than your opponent.

You might notice that you can't place a card in a caravan that already has a card in it. This might be for a few reasons;

• There's a difference between attaching a card to another, and stacking a card on top of another: Press the up and down keys to move along the heights of a caravan. Face cards can only be attached and number cards can only be stacked,
  
• You can't place two number cards of the same value in the same caravan

Aim to have 10/6 or 10/8 in each caravan, and attach a King to the 10 in 10/6 caravans, or to the 8 in 10/8 caravans. If you don't have any of the cards you need feel free to discard.
It's also worth having a few Jacks in your deck to use against your opponent.

The only reason I learned how to play Caravan was so I could 100% the game, and to make that easiest for myself I played against the easiest caravan opponent; No-Bark Noonan.

From what I've learned, No-Bark's deck has no 2's, Queens, or Jokers. He also only has three to four Jacks, and two to three kings. After you've placed your initial card in each of your caravans he'll use a Jack against you one to two times. Rarely three, very rarely none. After your first few moves he's very unlikely to use Jacks against you ever again in that game. I only saw him using a King against me three times out of thirty five games.
Also, sometimes he'll deliberately bust one of caravans. I have no idea why he does this.

The strat I use against him is to place 6's and 8's as my first card in each caravan, then replace any cards he removes. It's only after three to five moves that I actually start building my caravans. Unless he's particular nasty with his Jacks, or you're particularly unlucky with whichever cards you draw, you should be able to get to 26 in each of your caravans immediately. If not, don't forget to Jack or King any caravan of his that reaches 20, just to be sure that he doesn't sneak a win past you.

Caravan is a garbage game and the only reason you should play it is for the two achievements.

If there's anything I've missed or didn't explain right, tell me and I'll make any appropriate changes.