● GAME CENTER -- Play online, chat, invite friends, auto-match with random players
{ Real-time } Play online in real-time
{ Turn-based } Play online at your own pace
● VERSATILE -- Play offline vs. computer or against another person in 2-player mode
● CUSTOMIZABLE -- More options than any other backgammon app
● UNIVERSAL -- Supports iPad, iPhone, & iPod touch

Play & learn backgammon at skill levels from beginner to world-class!

Backgammon NJ HD is a full-featured game which uses an advanced, neural network-based, artificial intelligence. Play against a computer AI, another person in 2-player mode on one device, or online against friends & others. Using Tutor Mode & Hints, Backgammon NJ HD can show you how to improve your game.

Discriminating players will appreciate how well the AI plays. It uses a neural network trained on millions of positions, a bearoff database, & a match equity table to achieve strong gameplay that will challenge even expert players.


"[I] know strong bg play when I see it. This app is the strongest iPhone bg app I've played with by far. It does not cheat period. ...Analyzing these matches with eXtreme Gammon confirms a world class level of play with normal luck factors. If you are losing, get over it. So would 99.9% of the other backgammon players in the world. It is just that good. Learn from it." -Richard Munitz, Giant of Backgammon, #21 world ranking in 2009

"Backgammon NJ plays at an extremely high level with an excellent interface, and I often use it to practice on my iPhone when I am traveling. I recommend it highly to my students & friends." -Phil Simborg, Professional Backgammon Teacher & Player,

"I've played over 500 games now; I've checked about 5% of these against World Class Desktop programs (GNU, BGBlitz); and I've actually used some of the competition. NJ has the best interface & has more useful functions than any other backgammon apps out there."

"For serious backgammon players, Backgammon NJ is the way to go.", May 2012


This game is best for people:

• Who recognize the strength of neural network backgammon bots
• Who want to improve their game by playing against a world-class level AI
• Who will use the in-depth, technical features included in the app to prove that it is honest (
• Who won't expect to win consistently on the higher skill levels


• Neural network-based AI
• 2 game types: Standard Backgammon or Nackgammon
• 4 skill levels: Easy, Medium, Hard, Expert
• Customizable board design & checker colors
• Mersenne Twister algorithm for random number generation
• Doubling cube
• Single games or match play up to 25 pts
• Crawford rule for match play
• 1-player mode vs. computer
• 2-player mode on one device
• Game Center: Play real-time or turn-based online matches with friends & other players
• Chat with your online opponent
• Online Elo & Experience leaderboards
• Block list for auto-match
• Tap-to-move interface
• Highlighted checker movement options
• Hint & Undo
• Learn with Tutor Mode
• Game & dice stats, including Elo rating & ER
• Match info: GnuBG ID, win chances, equity, top 10 moves, cube decisions
• Email match files
• Practice mode with unlimited undo (1-player vs. computer)
• Manual match recording mode with unlimited undo & speed mode option
• Options to reverse board direction, resign, use one-tap moves, auto bearoff, auto finish, use Jacoby rule, & much more
• Match analysis (in-app purchase): Analyze past match files, view moves & errors for match, step through match, jump to position, play from position, save match files permanently


• If an online match ends for any reason, you'll receive the Elo pts you deserve. FAQ:
• Contact us for help:

What's New

Version 6.1.1

- Added arrow buttons to analysis move List to quickly jump to top and bottom
- Updated for iPhone X
- Bug fix for analyzing two matches in a row with different match lengths
- Bug fix for online play chat input line being covered by keyboard on iOS 11


- On iPhone X, to return to the Home screen, swipe up once on the Home indicator at the bottom of the board to activate it, and swipe up a second time on the Home indicator to return to the Home screen.

- If you're experiencing app crashes, it's most likely caused by Apple Game Center bugs. To prevent the crashes, do the following:

1) In BGNJ, under Advanced Options > Online Settings > turn OFF "Enable Game Center"
2) Force quit BGNJ (double-tap Home button and swipe away BGNJ)
3) Run BGNJ and play OFFLINE matches only

For more info, contact us directly:

Ratings and Reviews

4.4 out of 5

1.4K Ratings

1.4K Ratings



AI can look ahead like many reviewers noted. Not realistic, just a gadget that gets annoying.

To your reply: What you mention on your site basically states that the dice can be anticipated. The obvious proof that the app takes advantage of that fact is that it does make apparently senseless moves that later appear to be beneficial for the AI. Not sure why you made the choice to manipulate. It turns an otherwise nice and smooth Interaction design into a silly gadget.

2nd Reply: It is nice that you take pride in your game. Also I take pride in my play. I have played BG for 40 years all over the world with partners of various cultures and different strategic approaches. After a 100 or more games we usually always ended up more less 50/50. If I play your app rolling manual dice I win the AI at least 60/40. If the app runs the dice, I loose against the AI 40/60. So, to me, it is either a weaker or a cheating partner. As a professor for strategic management I would be interested how exactly it takes advantage, but as a player I get just bored. It is a pity as the Interaction Design is great and it runs very smoothly. This sentence, in your proofs, does not make sense: “If you prefer, you can play the manual roll game first and the auto-roll game second.” I uninstalled the app. Would not recommend.

Developer Response

1) The app is honest & has random rolls. Proofs here:

If you go through proof #2 step-by-step, you'll see that the app does *not* look at upcoming rolls.

Regardless of whether the rolls are automatic or manually input, the Expert AI will make the exact same moves for the exact same match position. If you actually took the time to go through and understand the proofs, then you would already know this.

2) In NO way do we ever state that the dice can be anticipated.

3) The AI isn't making "senseless" moves, as you state. It's making good moves that you don't understand. Post match positions to the BGonline forum ( and ask the experts there to explain why a certain move is better than another. Many of the top players in the world post at the BGonline forum, and many are quite young. The length of time that you've been playing has no bearing on your skill level.

4) If you read and follow all the steps listed exactly (, you'll understand What this statement ("If you prefer, you can play the manual roll game first and the auto-roll game second.") means. Following the steps, you've printed out the upcoming dice rolls (step #3), and you know the RNG Seed and roll numbers for your match. You can use the print out of rolls to play the manual roll game first by manually inputting the exact same rolls. Then afterwards, you can use the same RNG Seed and roll numbers to have the AI automatically generate the exact same list of rolls and play the auto-roll game second. If you do this, you'll see that the AI makes the exact same moves for the exact same match position, regardless of whether the rolls are input manually or automatically generated.

Regardless of whether you play the manual roll game 1st or 2nd, the results will be exactly the same. The AI makes the exact same moves for the exact same match position. To be even more clear, the only thing that the AI needs to determine what the best move is in every situation is a snapshot in time, a single static screenshot of the board which shows the current dice roll, checker position, and match score. It doesn't matter what dice rolls came before or come after that single snapshot in time.

It takes some technical know-how to do the above, but if you follow the steps exactly, you can do it.

Surprisingly good but not the place to find skilled competition


The reality is very few people are truly good at backgammon, so it appears computers cheat or dice aren't fair. No, you just need to improve. No app is good as XG for learning the game, but after playing this a while I've found there to be many useful features, clean interface, strong AI, and fair rolls. Trust me, play against a world champion and you will think they have rigged dice too. I've played against enough people on this app to confirm that there are a lot of weak players on here, the main downside of this app. And people play short matches, which misses out on much of the richness of backgammon. I would like a way to manually input an email address to send match files to, instead of having to use the Mail app. Analyze mode doesn't give enough info on cube decisions - is it No double because it's not good enough, or too good? And the dice rolls show up on the same side of the board, a bit confusing. But, it's a pretty well done app overall.

Developer Response

In Analysis mode, there are two types of doubling errors:

1) If it says "Error (No double)" in the status bar area or "(ND)" in the Move List, it means that you didn't double when you should have.

2) If it says "Error (Double)" in the status bar area, it means that you doubled when you shouldn't have. In this case, it's either "too good to double" or "not good enough to double". To tell which, look at the equity and compare it to +1.00 (if the cube is at 1). If the equity is > +1.00, then it's "too good to double". If the equity is < +1.00, then it's "not good enough to double". In the unlikely event that the equity = +1.00, then look under Advanced Options > Match Info to see the equity to 3 decimal places (before it was rounded to +1.00).


If you turn on One-Tap Moves (under Menu > Settings), it will do what you want.

Why the AI wins!! What you need to know!

love the techstuff

Let's get right to it. While the dice rolls against the AI are randomly generated, it is not "fair" because the AI can now "look ahead" and make moves based on what it already knows you are going to roll! That's why some reviewers are upset because the computer leaves blots and openings but you can never land on them because it looks ahead! Sadly, this is not the "best" learning tool because the AI will leave blots or make seemingly bad moves since it already knows what's going to happen. If you copy down the randomly generated rolls and then replay the game manually your winning percentage will increase. So...why four stars? Because YOU can look ahead too and make it a bit fairer. It's also a pretty good AI when you play in manual mode but it does "cheat" so deduct one star. It's lots of fun if you don't take it too seriously!

Developer Response

The app is honest & has random rolls. Proofs here:

If you go through proof #2 step-by-step, you'll see that the app does *not* look at upcoming rolls.


Jimmy Hu
48.8 MB
Requires iOS 9.0 or later. Compatible with iPhone, iPad, and iPod touch.
Age Rating
Rated 4+
© 2018 NJ
In-App Purchases
  1. Power User $4.99
  2. Analysis Package $2.99
  3. Online VIP $2.99


  • Game Center

    Challenge friends and check leaderboards and achievements.

  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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