Balance Variant
In order to reduce potential lopsidedness if an uneven distribution of intersection tiles appears during a game of Seismic, the following variant can be used. This variant adds some additional strategy to the base game by ensuring that each player receives the same number of valuable intersection tiles. You can download a nicely formatted, ready-for-printing pdf of this variant here.
Setup
Pull out all the intersection tiles except the +1 at the same time the quake tiles are separated from the deck. Mix the 6 quake tiles with the 6 simple highway tiles, but only remove five tiles from the game, shuffling the remaining six with the standard highway tiles (not the intersections). Flip 2 standard tiles face up (the starting tiles).
Next, separate the shuffled standard tiles into as many piles as there are players, and evenly distribute the intersections (face down) onto each pile:
For 2 players, each pile will have 30 standard tiles and 6 intersection tiles.
For 3 players, each pile will have 20 standard tiles and 4 intersection tiles.
For 4 players, each pile will have 15 standard tiles and 3 intersection tiles.
Gameplay
Each player takes a pile and shuffles it. On their turn, they draw a tile from their pile and may place it or one of the face up tiles. When a quake tile is drawn, the standard actions take place regarding how the quake affects the built roads, with the “flipping” player choosing the direction in case of a tie. The player who drew the tile then uses one of the face up tiles to place a tile, reducing the number of choices for themselves and everyone subsequently. After two quakes, there are no more tiles face up except the one being turned, and the player who turns up the quake tile does not get to place a tile or marker; play moves to the next person clockwise. Close to the end of the game, it is possible that a player who has turned up more quake tiles will not have any tiles to play when it is his turn; this player is skipped through the end of the game.
Fun with Seismic tiles
The 74 highway/intersection tiles (there are 6 Quake tiles) can be used in all sorts of interesting ways. A great brain exerciser is to try to achieve goals such as a perfect game, highway system, or hexagon. For these activities, it’s best to put away the markers, tell your friends to get the hell away from you so you can focus, and then start laying out tiles. For most of these, treat the San Andreas tile as a six-sided intersection.
Maximum Scores and the Perfect Game (Scoring)
The total number of points possible per game is 272 total (assuming no quake tiles or shared roads). However, scoring that many points would take 24 markers, and each player is limited to 20 markers each. That lowers the maximum score potential by 10 to 262, which would be considered a perfect 2 or 3 player game. Up to three people could theoretically score the 272 points each, if each road was shared by all three players (requiring each completed highway to be at least three segments long. While theoretically this is possible, it is unlikely that a pattern could be construed with the variety of highway tile types that would allow for the perfect game.
How was the maximum score calculated?
There are 90 segments on the highway tiles, for a total of 90 points. There are the number of segments as there are points on the intersection tiles, so the possible points on each intersection is the square of the intersection (i.e. a +6 intersection is 36 points). Adding these together results in the maximum number of points that can be scored.
The Perfect Highway system
A completely closed highway system (no open ends, all highways terminate in an intersection) is fairly simple to achieve using less than the entire set of tiles in the Seismic box. However, using all the tiles is again unlikely, given the distribution of the tile types.
The Perfect Hexagon(s)
A 6x6x6 hexagon of hexagons requires 91 hexes, while a 5x5x5 hexagon requires 61 hexes, a 4x4x4 hexagon requires 37 hexes, a 3x3x3 hexagon requires 19, a 2x2x2 requires 7, and a 1x1x1 requires 1 hex. Therefore, a single set of Seismic tiles (74 highway/intersection) can produce at most 1 5x5x5 hexagon, with several pieces left over. This is possible to create legally quite easily, but creating a perfect 5x5x5 hexagon that is closed is another matter entirely.
Another, more interesting option would be to create two 4x4x4 hexagons using ALL the pieces. This is challenging when there are open paths, but feels impossible if the requirement is that they are closed.
Other Shapes
Snowflake designs are a natural fit to hexagons, but again make closed systems nearly impossible. Double or triple thick tile sets (three columns or rows) are a totally different type of challenge.