Absolute Pin
Alekhine’s Gun
Back-rank Mate
Doubled Pawn
Have two pawns of the same colour on the same file
O-O-O
Castle queenside
O-O
Castle kingside
Check
Put an opponent in check
Checkmate
Win a game
Chop Wood
Make a capture or exchange
Promotion
Advance a pawn to the eighth rank
Underpromote
En Passant
Perform an en passant capture
Double Check
Deliver a check by two pieces at the same time
Learner
Complete all the tutorials
Piece Collector
Capture 100 pieces
Epaulette Mate
Deliver checkmate where the King is blocked on both sides by his own Rooks
Fool's Mate
Scholar's Mate
Octopus
Place a White Knight on e6
Spanish Bishop
Develop a White King Bishop to b5
Tournament Amateur
Win a tournament
Problem Solver
Complete 50% of the chess challenges
Elo
Beat an opponent with an Elo rating higher than yours
Stranger Danger
Create a random online game
Friendly Fire
Issue an online challenge to a friend
Bobby Time
Play a game using the Fischer timer
Queen Sacrifice
Family Fork
Using a Knight simultaneously attack the enemy King and Queen
Elo Elo
Beat an opponent with an Elo rating more than 75 higher than yours
Tournament Pro
Win 5 tournaments
Blind Pigs
Manoeuvre a pair of Rooks onto your opponent’s second rank
Stalemate
Draw a game by stalemate
Boden's Mate
Tournament Champion
Win a 32 player tournament
Elo Elo Elo
Beat an opponent with an Elo rating more than 150 higher than yours
Chess Champion
Beat the computer on Grandmaster difficulty
Problem Solved
Complete all the chess challenges
Tournament Master
Win 20 tournaments