Hebi is a Nikoli puzzle in which the aim of the game is to add two sequences (snakes) of 1 to 5 to a grid. The numbers will have to be placed in a specific way based on the clues and on the rules of the snakes.
Hebi could be played on any grid and with bigger snakes as well. The difficulty level is usually determined by the length of the snakes and the size of the grid, but the given clues can affect the difficulty level as well.
The rules are as follows:
- Place 2 sequences (snakes) of 1 to 5 in the white cells of the grid. Each sequence has to be sequentially linked (so from 1 to 5).
- Snakes cannot touch each other. If they do they will fight and kill each other. (Yes, these are no ordinary numbers. ;) )
- A snake can see all the cells in front of it up to the edge of the map or the next black cell. Its front is the direction the followed from 2 to 1. A snake cannot be allowed to see any part of the other snake within its cells of vision or else it'll attack.
- Black cells sometimes show what number has to be next to them in the direction of the arrow.
Hebi is usually a fairly easy puzzle to solve. The black cells will immediately give you a place to start, which will then in turn provide you with an opportunity to do some easy deduction work. It may take a little trial and error in some cases, but most puzzles are usually solved in a few minutes.
Hebi's one of those puzzles that doesn't seem to have too many adaptation options, at least not in terms of varied themes. The obvious one is to simply use snakes in your campaign. Alternatively you could use increasing power sources, distribution of land (enemies don't want to touch borders or see borders on their main plot), and similar adaptations.
For my example I went with dividing 2 squads of inanimate suits of armor. My character is faced with a relatively small room. She's told to add suits of armor in the room, given the instruction on how to solve a Hebi puzzle, and the knowledge that failing to follow the rules will have explosive consequences. All the regular rules apply, but instead of going from 1 to 5 you put them in a color order (blue, green, yellow, pink, orange). You could still assign numbers to the colors to keep it easier.
As long as she sticks to the rules and manages to solve the puzzle she'll be fine, but if she messes up at any point the suits of armor will come to life with a bright flash, start attacking each other, and then turn to any other remaining enemies, which would be her.
Depending on how you adapt this puzzle you might wish to keep in mind whether or not your puzzle needs a unique solution. If you're hiding secret paths, loot or other elements to spots that are supposed to remain untouched it's definitely best to have a unique solution.
Take my puzzle as an example, if you change the dark brown, top left cell to a regular one the possible solutions increase tremendously.