Twilight Imperium is one of the best games I have ever played. As a student at college, my friends and have 1-2 board game nights per week; with Twilight Imperium and Acquire being the most played games. I would highly recommend this game, though the learning curve is rather steep (an hour at to learn the rules) and the game takes a long time to play (4+ hours). If you are looking for a conquest game like RISK, stop reading now. Twilight Imperium is based on maneuvering, preparation, and diplomacy with few significant battles in the game.
The game is played to victory 10 points and unlike most war games, conquest is not the only means of victory. Points are acquired through capturing planets but also "researching" technology, and political decisions. The method of determining turn order is also quite original. Each player chooses a card (1-8) which in addition to being the order in which the players play, gives each player a special ability for that round. To further add interest each card has a secondary ability which all the other players can use when the player owning the card uses it. As a result not only are broad discussion (like conquest or technology) important but every turn can be critical as the players ability to ace often depends directly on when and how the other players act. This may seem as if it would slow the game, but a restriction on how many turns a player can take per round keeps the game moving nicely but keeps strategy extremely important through out.
This is not to say I don't have a few complaints about the game. The first couple of times we played we noticed some imbalances which led to certain having a definite advantage and the game always trending in the same way. There are 3 ways to get these points. Every player can complete common objectives, a new one being revealed each turn. A player gets 2 points every time they get the 8 card, and a player has a secret objective which can be worth two points. Our problem was that everyone accomplished the same common objectives. Because the 8 is so valuable, whoever went first had to take the 8, the person on their right then always took the 1 (and so they chose first next turn), so they could get the 8 next turn. Anyone who failed to follow this pattern automatically became 2 points behind, and never could catch up. The result is that there is little strategy to taking the 8 or the 1. Finally the secret objectives vary greatly in difficulty. As a result players who got easy secret objectives, or got to go first were far more likely to win. In fact in our first 3 games (5 players), the player who went first won 2 of them, and the only player that completed his secret objective in the 3rd game, won that one. At this point we were ready to give up on the game but instead we played around with the rules and came up with a slightly variation which greatly helped improve the game. If you do buy this game I highly recommend trying this variation after playing the normal rules a couple of times.
Many of these rule variations were taken from the Twilight Imperium Rule Variations which can be found (...)
1) The 8 card's text has been modified to the Game Option: Ancient Throne which gives a player 1 point for controlling Mecatol Rex. This modification greatly increases the strategy in choosing the 8 or 1.
2) Long War Variant: Play to 14 victory points. This will be necessary due to rule change # 3.
3) A player receives 2 victory points if they capture a planet in an opponent's home system. A player may only get points for a home system once. If the owner of the home system was not in control of the planet when it was captured this is reduced to 1 point. The reason for this rule was to encourage conquest (something that was seriously lacking in our previous games). The point reduction rule is to help prevent two players from allying to take a home system (since one of the players will not get all the points).
4) Every player receives 2 secret objectives. After creating the board but before the first turn each player must choose and discard one of them. This rule helps reduce the problem of unbalanced (in terms of difficulty) secret objectives.
5) You may only complete public objectives if you control all the planets in your home system (you may complete other objectives however). This allows players to slow down a player who gets too far ahead.
6) Destroyers get 4x Anti-fighter barrage. Destroyers are the weakest units in the game; this makes them a little better, but still hardly worth using.
7) The common objectives are laid face up on the table (you may still only complete the first after the first turn, second after the second, etc). This reduces the luck involved near the end of the game, as every one knows what is coming.
8) Technology can be purchased with influence or resources (but no combination). This rule helps balance the planets so everyone has more equal resources.
These rules seem to be very effective. While most players still get all of the common objectives, winning the game now depends on controlling Mecatol Rex, completing secret objectives or taking home systems. Players have been very successful using any combination of these three methods, and no race has done better or worse than any other. While these may seem to lead to large amount of conquest, this has never been the case, with only 3-10 major battles occurring in 4 player games.