Steam Tunnel
Steam Tunnel Rulebook
Table of Contents
Table of Contents
Contained in this Game
The Steam Tunnel deck contains 48 cards, including 44 Tunnel cards and 4 Point cards.
You Will Also Need
- 2 to 5 players, and about 20 colored stones for each player. Each player needs a different color of stone.
- A pencil and paper, to tally scores at the end.
The Basics
Players will explore and capture the steam tunnels connecting various points in a titanium mine under the surface of Jupiter's volcanic moon Io. The longest tunnels and the best end caps score the most points.
Setup
Remove the four Point cards (the ones with numbered end caps) and shuffle the rest of the deck. Build a board of 36 cards in the shape indicated in Figure 1, placing the Point cards as shown, and the other cards facedown. 12 of the cards will not be used.
Figure 1: Starting layout. Arrows show how the board wraps.
Game Overview
Players will take turns flipping over cards and placing stones on the board, trying to capture the best tunnels. Each card has 6 entry points that depict tunnel segments and dead ends.
The board wraps around. Wherever a tunnel leads off one side of the board, it comes back on the opposite side. This is because Io is such a small moon. Okay, there's no real reason. But it does.
Facedown cards act as straight tunnels, and all tunnels that connect to them pass straight through. This really only matters at the end of the game, when some cards will be permanently facedown because players have "buried" them.
Playing
Determine randomly who will go first. From there, play passes to the left. On your turn, you will flip one card and place one stone.
Start by flipping up one facedown card. (If you can't flip over a card, the game is over.) Because many cards are asymmetric, the way you flip this card will determine how it connects to the cards around it. Do this without looking: you don't get to choose.
Next, you may place one stone on the board. You may do this to buy, or to bury. You may also skip placing a stone, but you will probably never do this unless there is nowhere to put one.
Buying a Segment
Each Tunnel card has 2 or 3 segments of tunnel. To buy a segment, place a counter on that segment. At the end of the game, the player who owns the most segments of each tunnel will get the points for that tunnel. If players are tied for ownership, they divide the points evenly (using fractional points if necessary).
You can't buy a segment that's already owned, but you can buy other segments along the same tunnel. The black end caps are not tunnel segments, and can't be bought.
Closed Tunnels
You can't place a stone in a path that's closed, i.e., a path whose entire route is known. This is the case even if you closed the path with the card you turned over, so you may find yourself accidentally closing a tunnel before you have the chance to buy part of it. For example, suppose you went second and turned over this card (the rest of the board is facedown):
[Figure: a tunnel card turned over by the second player, with the segments numbered 1 to 5 and the arrow marking the card just flipped.]
Assuming they're not occupied, you could place a stone on segment 2, 3, or 5, but not on segment 1 or 4. You closed that path by flipping this card, and you can't buy a segment in a closed path.
Notice, you are not restricted to playing on the card you just flipped. You can buy a segment along any open path, not any faceup card.
Burying a Card
Instead of buying a tunnel segment, you can place a stone on a facedown card to bury it. A buried card can never be flipped over, and all tunnels that connect to it lead straight through it.
You can bury cards to guarantee your hold on particular tunnels, or sometimes to steal points from other players. Burying cards also shortens the game. However, you do not "own" a card you have buried, so it won't help you capture a tunnel you don't already own.
Scoring
When the last card is flipped over, or when no more cards can be flipped, the game is over. If you flip the last card, you will not be able to play a stone because all the paths will be closed.
The point value of every tunnel is equal to the total values of its end caps multiplied by the number of segments in the tunnel. Black end caps are "dead ends" and worth zero, so if a tunnel connects nothing but dead ends, it is worth no points.
Hint: To aid in scoring each line, start at any end point and count the segments in the line, picking up the stones as you go. When you have counted all the segments, you will hold all the stones and can easily tell who controlled the line, and how to assign the points.
Scoring Example: A path containing 5 segments connects two end points worth 3 and 4. The sum of the endcaps is 3 + 4 = 7, the length is 5 segments, and so the value of the tunnel is 7 * 5 = 35 points.
Another Example: A large tunnel containing two forks connects end caps worth 2, 2, 3, and 0. There are a total of 8 segments in the tunnel, and three players share it because each of these players owns 2 segments. The tunnel is worth (2 + 2 + 3 + 0) * 8 = 56 points, so each player scores 56 / 3 = 18.67 points.
One More Scoring Example: Assume this is a complete, but very small board. The value of each tunnel is detailed below.
- Path 1: This is a simple one. It connects a 4 and a 0, and its length is 1 segment, so it's worth (4 + 0) * 1 = 4 points.
- Path 2: 2 segments and connects two dead ends. (Remember, the board wraps around, and facedown cards count as straight tunnels.) It's worth 0 points.
- Path 3: 7 Segments and 4 end caps: 2, 0, 4, and 0. Value: 42 pts.
- Path 4: 9 Segments and 3 end caps: 3, 0, and 4. Value: 63 pts.
- Path 5: 7 Segments and 3 end caps: 3, 2, and 4. Value: 63 pts.
- Path 6: 5 Segments and 2 end caps: 3 and 2. Value: 25 pts.
- Path 7: 1 Segment and 2 dead ends. Value: 0.
Variations
It took us a while to get this game to the point that we really loved it. Along the way we discarded several inferior versions which we will now describe as "variants" to simulate added value. Enjoy!
- Killer Dead Ends: For a game with more variance in the total scores, and more cutthroat tactics, try this version. If a tunnel connects to even one dead end, it's worth nothing.
- Not-So-Killer Dead Ends: This is a slightly less deadly version of the game above. A path is worth nothing if it doesn't connect at least two point caps. In other words, it can still connect to dead ends, but it must have at least two ends that are worth points.
- Simpler Paths: For this variant, remove some or all of the cards that contain forks. The remaining Tunnel cards will have fewer forks and proportionally more dead ends.
- Pity Scoring: Dead ends are worth 1 point, not zero.
- Shuffled Board: This is a variation we've never tried, but it sounds kind of neat. Shuffle the Point cards into the deck, and deal a 7 x 7 board with a void in the center (treat this empty space as a permanent face-down card). Play the game normally, revealing the Point cards as you go. You might want to make dead ends worth 1.