Here’s a screenshot example from Flashrolls<\/a>.<\/p>\n There are many other implementations. For example, you can play at Mindjolt, where it is called ConfuseBox<\/a>.<\/p>\n For a variation, based on pipes instead of power, try Rotate2<\/sup><\/a>. Rotate<\/a> is another version, based on photographs, but that’s out of the scope of this article.<\/p>\n There are a number of variations of the game. Here I list some that I have found, and some that I have conjectured could exist.<\/p>\n I originally played a variation of this game (which I haven’t bothered to try to find again) which included barrier walls between some parts of the circuit, which could not be crossed by wires.<\/p>\n Flashrolls’ version of the game adds walls during the game as a form of hint, if requested.<\/p>\n The original version I played allowed you to mark cells with a flag. That allowed you to note which cells were solved and should remain fixed, and which you still needed to concentrate on. This made solving the larger puzzles much less cumbersome.<\/p>\n Rotate2<\/sup> permits cycles in the graphs.<\/p>\n For the other implementations, I haven’t noticed any game rules that explicitly forbid cycles in the path. I also haven’t noticed any solutions that have cycles in them.<\/p>\n Most versions have a concept of a power cell. They light up the wires and bulbs that are connected to the power cell, and not the ones that are disjoint from it. <\/p>\n These versions of the puzzle do not permit disjoint solutions; every node in the graph must be connected (indirectly) to every other. Adding a Power Cell provides a simple visual reminder of that. When considered that way, it becomes clear that the Power Cell is no different to any other cell; any one of them could be marked as the power-cell, and it would have the same solution.<\/p>\n If you don’t<\/em> have Power Cells, you need to decide if disjoint graphs (with no half-connected edges) are a valid solution. Rotate2<\/sup> permits disjoint solutions.<\/p>\n Some versions include a cross cell (with wires that point in all four directions). Such a cell never needs to be rotated, as it is rotationally symmetric.<\/p>\n Some versions permit cells that have no wire in it. Like a Cross cell, it need not be rotated.<\/p>\n I have not seen this variation, but there is no reason why there couldn’t be two distinct (and disconnected) wires in a single cell. Such a solution could form cross-over or double-corner pieces, rather than a simple cross cell.<\/p>\n I have not seen this variation either, but notionally, you could have a cell that morphs to accept any connections that attach to it.<\/p>\n I haven’t seen this, I’m just saying, it’d be cool. That’s all.<\/p>\n This table describes all the types of pieces, to act as a glossary, for later.<\/p>\n Generally, they are solved from the outside in, with Straight and Tee pieces having only one permissible orientation along the outside edges.<\/p>\n From there, it is generally pieces that are wedged in a corner that are solved next.<\/p>\n![\"Circuit](\"http:\/\/www.somethinkodd.com\/oddthinking\/wp-content\/uploads\/2008\/09\/circuit-game-unsolved-300x170.png\" "\\"Circuit")
<\/a><\/p>\nVariations<\/h3>\n
Walls<\/h4>\n
Flag Cells<\/h4>\n
Permit Cycles?<\/h4>\n
Power Cells<\/h4>\n
Cross Cells<\/h4>\n
Empty Cells<\/h4>\n
Distinct Wires<\/h4>\n
Wildcard Cells<\/h4>\n
Hexagonal Cells<\/h4>\n
Taxonomy<\/h3>\n
\n
\n Name<\/th>\n No. of Wires <\/th>\n No. of Orientations <\/th>\n Notes<\/th>\n<\/tr>\n \n Empty<\/th>\n 0<\/td>\n 1<\/td>\n Does not appear in all implementations. <\/td>\n<\/tr>\n \n Bulb<\/th>\n 1<\/td>\n 4<\/td>\n Doesn’t actually have any special meaning. Merely a “dead-end” piece.<\/td>\n<\/tr>\n \n Corner<\/th>\n 2<\/td>\n 4<\/td>\n <\/td>\n<\/tr>\n \n Straight<\/th>\n 2<\/td>\n 2<\/td>\n <\/td>\n<\/tr>\n \n Tee<\/th>\n 3<\/td>\n 4<\/td>\n <\/td>\n<\/tr>\n \n Cross<\/th>\n 4<\/td>\n 1<\/td>\n Does not appear in all implementations.<\/td>\n<\/tr>\n<\/table>\n Manually Solving the Puzzle<\/h4>\n