Leaders are an optional rule in the game. They add a significant amount of complexity to the game, so you should not use the option when teaching it to new players. Once accustomed to the vanilla rules, however, you should strongly consider using Leaders. They give the game more depth and are an element in balancing the races, which is the reason why I took them into account in the race strategies above. Let’s take a look in more detail to the Leaders.
The Admiral is pretty straightforward and a valuable man to have in every space battle. Not only does he give the ship he’s on an additional die, he also prevents enemy fleets from retreating and gives Dreadnoughts +1 movement. So, you want to place the Admiral always on the ship with the lowest hit number to maximize its efficiency. Having an Admiral allows you to have Dreadnought around that doesn’t slow your fleet, too, so it’s worth considering if you want to get one in that case.
Generals are arguably the weakest leaders in the game. They give defending Ground Forces an additional +1 on combat rolls, reroll up to two dice attacking and make bombarding them much harder. I find the last ability of the General the most worthwhile, because many games tend not to have excessive amounts of ground combat. Put the General on planets that are likely to be invaded so the bombardment beforehand doesn’t deal too much damage. This becomes powerful, though, when combined with a Scientist so there can’t be any bombardment at all when Planetary Defense Systems are present and one can hardly defeat the Ground Forces of the General anymore.
This leader provides you with a range of possibilities that are not to be underestimated. First, any tech discount of the planet he’s on counts double, so you will be able to purchase tech very cheaply if you deploy him right. Second, planets with Planetary Defense System and a Scientist can’t be bombarded anymore. Third, building a Space Dock costs two resources rather than four. Fourth, you receive +1 for Planetary Defense System die. Using the Scientist right is a matter of in-game logistics. He needs the most attention of all leaders because you can’t just stick him with a precious objective and leave him there. Bring him along when producing Space Dock, throw him on planets with tech discount appropriate to the tech you plan to purchase and bring him to the front when in need to defend a planet.
The Diplomat has two abilities. The first is seldom used and allows a fleet containing him to move through an enemy fleet, provided the enemy allows it. You can sometimes surprise common enemies this way or prevent a certain victory by showing off at the game leader’s backyard surprisingly, but in most cases the Diplomat is thrown down on the surface of a valuable planet to protect it from invasions. Saves Planetary Defense System and Ground Forces. Also, the Diplomat has an almost certain appointment with Mecatol Rex once the objective pops up. Every other objective that requires you to hold planets is easy game for the Diplomat, too.
The Agent is a versatile, often-underestimated leader. Enemy Planetary Defense System don’t fire on invasion groups he is accompanying. After a successful Invasion Combat, he allows you to take over any enemy Planetary Defense System or Space Dock on the planet rather than scuttle them, provided you haven’t reached your plastic limit (don’t forget to scuttle one of yours the round before if necessary). And you may sacrifice him as a “Sabotage” action card. This last option is often dismissed too easily since you then will not be able to use the Agent any longer which seems a disadvantage against other guys still around with three leaders. But consider: a General or Admiral is always in risk of dying or capture. And many action cards have such a deadly effect on your plans and abilities to win the game that the Agent is a small price to pay. Don’t use him because an action cards seems inconvenient to you. Save him for the real stuff. Don’t fear, when you are winning everyone will throw their really hurting action cards at you, so you will have options for the guy.