Difficulty definitions
Easy Difficulty
Easy puzzles will rely only on the following:
- Naked singles
- Hidden singles.
These puzzles may have options for higher level solving, but they will not be necessary to solve the puzzle. There will always be several hidden singles in these puzzles in order to make the hunt interesting and fun.
Medium Difficulty
Medium puzzles have at least one of the following:
- Naked doubles
- Naked triples
- Hidden doubles
- Hidden triples
- Pointing pairs (or triples)
- Box-line reduction
The number of solves requiring non-single strategies will be limited. Each medium puzzle will use at least one double, triple, pointing, or reduction strategy to solve. Other strategies may be possible, but not necessary to solve.
Hard Difficulty
Hard puzzles will use all strategies a medium puzzle uses- just with greater frequency. There are no higher level solves needed to solve a hard puzzle, but they can often use higher level solves.
- Naked doubles
- Naked triples
- Hidden doubles
- Hidden triples
- Pointing pairs (or triples)
- Box-line reduction
Tough Difficulty
This is where things start to get interesting. For each tough puzzle there will be at least one of the following strategies necessary to achieve the solve:
- Bivalue Universal Grave (BUG)
- Unique Rectangles 1
- X-Wing
- Y-Wing
- Chute Remote Pairs
- Simple Coloring
- Naked Quads
- Hidden Quads
- Swordfish
- XYZ Wing
Diabolical Difficulty
These puzzles are for the seasoned player. For each diabolical puzzle there will be at least one of the following strategies necessary to achieve the solve:
- X-Cycles
- XY-Chain
- 3D Medusa
- Jellyfish
- WXYZ Wing
- Aligned Pair Exclusion
- Hidden Unique Rectangles
- Unique Rectangles 2+
Extreme Difficulty
Remember, you wanted this. For each extreme puzzle there will be at least one of the following strategies necessary to achieve the solve:
- Grouped X-Cycles
- Exocet
- Finned X-Wing
- Finned Swordfish
- AIC (Alternating Inference Chain)
- Almost Locked Sets
- Digit Forcing Chains
