Encyclopedia of Opening Blunders – learn to play chess by learning the opening mistakes and traps that have been discovered over time. The program is designed for studying the blunders in more than 40 openings and contains over 1,250 instructive exercises of varying difficulty from practical games.

This course is in the series Chess King Learn (https://learn.chessking.com/), which is an unprecedented chess teaching method. In the series are included courses in tactics, strategy, openings, middlegame, and endgame, split by levels from beginners to experienced players, and even professional players.

With the help of this course, you can improve your chess knowledge, learn new tactical tricks and combinations, and consolidate the acquired knowledge into practice.

The program acts as a coach who gives tasks to solve and helps to solve them if you get stuck. It will give you hints, explanations and show you even striking refutation of the mistakes you might make.

Advantages of the program:
♔ High quality examples, all double-checked for correctness
♔ You need to enter all key moves, required by the teacher
♔ Different levels of complexity of the tasks
♔ Various goals, which need to be reached in the problems
♔ The program gives hint if an error is made
♔ For typical mistaken moves, the refutation is shown
♔ You can play out any position of the tasks against the computer
♔ Structured table of contents
♔ The program monitors the change in the rating (ELO) of the player during the learning process
♔ Test mode with flexible settings
♔ Possibility to bookmark favorite exercises
♔ The application is adapted to the bigger screen of a tablet
♔ The application does not require an internet connection
♔ You can link the app to a free Chess King account and solve one course from several devices on Android, iOS and Web at the same time

The course includes a free part, in which you can test the program. Lessons offered in the free version are fully functional. They allow you to test the application in real world conditions before releasing the following topics:
1. Rare variations
1.1. 1. g3, 1. b4 ...
1.2. 1. b3
1.3. 1. d4
1.4. 1. d4 Nf6
1.5. 1. d4 Nf6 2. Nf3
2. Alekhine's defense
3. Benoni defense
4. Bird's opening
5. Bishop's opening
6. Blumenfeld counter-gambit
7. Bogo-Indian defense
8. Budapest gambit
9. Caro-Kann
10. Catalan system
11. Center gambit
12. Dutch defense
12.1. Dutch defense
12.2. Iljin-Genevsky system
12.3. Leningrad system
12.4. Staunton gambit
12.5. Stonewall variation
13. English opening
14. Evans gambit
15. Four knights' game
16. French defense
16.1. French defense
16.2. Classical variation
16.3. Tarrasch variation
16.4. Winawer variation
17. Grünfeld defense
18. Italian game & Hungarian defense
19. King's gambit
20. King's Indian defense
20.1. King's Indian defense
20.2. Classical variation
20.3. Fianchetto variation
20.4. Four pawns' attack
20.5. Saemisch variation
21. Latvian gambit
22. Nimzo-Indian defense
22.1. Nimzo-Indian defense
22.2. Leningrad variation
22.3. Rubinstein variation
22.4. Saemisch variation
23. Nimzowitsch defense
24. Old Indian defense
25. Philidor's defense
26. Pirc-Robatsch defense
27. Queen's gambit
27.1. Queen's gambit
27.2. Queen's gambit accepted
27.3. Albin counter-gambit
27.4. Cambridge-Springs variation
27.5. Exchange variation
27.6. Orthodox defense
27.7. Lasker defense
27.8. Tartakower defense
27.9. Ragozin system
27.10. Semi-Slav defense
27.11. Semi-Tarrasch defense
27.12. Slav defense
27.13. Tarrasch defense
27.14. Variation with 5. Bf4
28. Queen's indian defense
29. Queen's pawn game
30. Reti opening
31. Petroff's defense
32. Ruy Lopez
32.1. Ruy Lopez
32.2. Berlin defense
32.3. Bird's defense
32.4. Breyer variation
32.5. Chigorin defense
32.6. Classical defense
33. Scandinavian defense
34. Scotch gambit & Ponziani's opening
35. Scotch game
36. Sicilian defense
37. Three knights' game
38. Two knights' defense
39. Vienna game
40. Volga-Benko gambit

Recent changes:
* Added Japanese, Hungarian, Norwegian and Swedish
* Added notifications settings; select notifications you want to see in the Practice
* "Go" floating button on the home screen now opens the first new exercise
* Added Instagram share for puzzles
* Improved dark theme support, you can now use "Follow system" option to match your system theme
* Make statistics colors in the light theme more bright
* Copy full exercise PGN to the engine after solution
* Various fixes and improvements