Triplanetary Review

Triplanetary Review

Review by David Lent

Steve Jackson Games has published the new edition of Triplanetary. This was originally designed by Marc Miller and released in 1973 and 1981 by GDW Games. It’s a space ship combat game that uses vector movement by drawing vectors on an erasable map. The new version has the original rules plus an optional advanced combat system. In addition, it now has two huge dry erase maps and big 5/8” counters. Triplanetary can be played by 2-4 players and has 10 scenarios plus campaign rules. I do not recall if the original version had campaign rules or if these are new.

The components and box for triplanetary all have the original 1970’s flavor to them. This game looks very similar to the original, but with much better components. The maps are much larger and have bigger hexes and now are made of better dry erase board material. Difficult to erase grease pencils are no longer used and instead easy to erase dry erase markers are included. The map has basically the same features as the original. All the same celestial bodies such as the Sun, planets and asteroid field are there along with weak or strong gravity arrows. In addition, the celestial bodies that have bases have a line printed around them showing the range they can detect ships out to. One thing that is immediately apparent about the map is that it is printed on a white background just like the original. This is probably for the best, because the arrows drawn with markers would be hard to see on a black background. The counters are now a larger 5/8” and still have 1970’s looking artwork on them. I really like the retro look of this game.

What makes Triplanetary unique among all the space ships games made over the years is its unique vector movement. Space ships travel like bullets in this game, just like in real life. If a space ship is moving at a speed of two, it continues moving at a speed of 2 every turn unless fuel is expended to alter the last hex in its predicted course by one hex or gravity acts upon it. Usually, the player will draw a dotted arrow to show its predicted course and then a solid arrow with its final course. Any time the course is altered one fuel is used. Fuel is very important in this game. Most ships have limited fuel and you can only refuel from a tanker, friendly orbital base or planetary base. In extreme cases, you can disable an enemy ship and match course with it to steal fuel or cargo. It’s best not to run low on fuel, because you may have to use plenty of fuel to rendezvous with a tanker or slow down to go into planetary orbit and land. E.G. If you are moving at a speed of 5 and need to go into orbit, it will cost you 4 turns and 4 fuel to slow down to speed 1 so you can enter orbit.

There are two combat systems in this game. The original and the advanced combat system. First, let’s talk about what can cause damage in this game. It’s guns, nukes, mines, torpedoes, colliding with asteroids and ramming. Mines are bundles of explosives that continue on the same vector as the ship that launched them. They detonate when a ship or group of ships pass through its hex. Torpedoes work like mines, except they can accelerate one or two hexes in any direction when launched, they damage only one target that passes through their hex and self-destruct after 5 turns. Nukes maintain the original vector of the ship launching them and last 5 turns before self-destructing. Any ship, base, etc. that enter its hex is automatically destroyed. Nukes can be shot down though. Ramming equally damages both ships and asteroid field collisions cause damage on a roll of 5 or 6.

The gun combat table uses modifiers for range and relative velocity difference. Range is obvious to wargamers, but relative velocity difference needs some explanation. Relative velocity is determined by plotting both velocity vectors from a common point and counting the hexes between their endpoints. For each hex difference greater than 2, the die roll is reduced by 1. After the modifiers have been applied to the dice roll, the combat odds are determined and the results are read from the combat damage table. The results can be no effect, DX or eliminated. DX means the target is disabled for X turns and may not change course or fire.




Triplanetary’s optional advanced combat systems allows weapon damage, drive damage, structural damage and looting to occur. This allows cases where a damaged ship may be able to fight, but not maneuver and vice versa. In addition, structural damage can eventually lead to the destruction of a ship.

The scenarios in Triplanetary help a new player slowly learn the game by having learning scenarios through advanced scenarios. In addition, the wealth of scenarios gives Triplanetary a lot of replayability.

The first two scenarios help players practice the movement, gravity, landing and orbiting rules. After that, the rest of the rest of the scenarios have combat, piracy, alien fleets, mutinies, interplanetary war and prospecting. There is never a dull moment in this game and the scenarios ensure you always have an interesting mission to play.

If players wish to play Triplanetary as a campaign, there are rules to do so. There are purchasing tables for buying ships and weapons, etc. However, fuel is free to reduce bookkeeping. In addition, there is information about playing as a prospector, space patrol, merchants or pirates. Games can be played for a specified number of turns or sessions and victory is calculated by the players’ net worth. A referee may be used to stop players from doing unrealistic behavior.

Triplanetary has stood the test of time, because its unique vector system of movement is highly addictive. Just moving your ships around the board is a lot of fun. In addition, moving your ships optimally requires lots of thinking ahead and as such movement is very strategic. Your not just plotting against your enemy, but you’re carefully plotting your own maneuvers so you don’t run out of fuel. I’m delighted that you have to use vectors in this game. When I first learned vectors in physics class during engineering school, I thought I would never use them since I’m a computer engineer. I’m glad this game has proved me wrong. I’m surprised that no solitaire scenarios were added to the new edition though. It would have been really cool to have a scenario where you have to move through the gravity field of several planetary bodies and land on one of them within a specified period of time. Overall, this is unquestionably the most interesting space ship combat game I have ever played and I highly recommend it.

Buy your own copy here.

View the components in the unboxing video below: