Originally, everything had an initiative value called "thrust." Your command ship was the slowest, then cruisers, frigates, and fighters were the fastest. What this meant was that all the fighters in a combat fired first and resolved all hits, then frigates, then cruisers. Each ship type was good against another ship type, bad against another type, and average against itself. Hits were determined by d6 dice rolls.
Fighters were good against cruisers and hit them on a 3+ and poor against frigates and hit them on a 5+.
Frigates were good against fighters and hit them on a 3+ and poor against cruisers and hit them on a 5+.
Cruisers were good against frigates and hit them on a 3+ and poor against fighters and hit them on a 5+.
Fighters had 2 shots each, frigates 3, and cruisers 5. Each ship could target anything it wanted, and in fact could split it's firepower on different targets as it saw fit, however shots that did excess damage were wasted. So if you used 5 shots to kill something and only needed 3 and scored all 5, 2 of those would be wasted and the damage would go nowhere. We wanted to design a system where there were tactical choices and a system of risk vs reward.
While I can say that our intent was admirable, or execution did not work. At all. The system was a disaster because it didn't accomplish the most important aspect of simulated combat in any game. It wasn't fun! With each ship targeting different things and each battle having as many as 4 initiative steps, combat took forever as dice were rolled in separate piles over and over and combat dragged and slowed the game down to a crawl. Because of this, the combat system was scrapped and painstakingly redesigned to our current system.
The first things that had to go was targeting and initiative values. Targeting makes sense thematically, but just slowed things down too much, so we put the targeting in charge of the defender, rather than the attacker. Now, each fleet of ships has a ship order ranging form 1-4. The ship in the #1 position is the "Point Ship" and takes all damage until it is destroyed, with overflow damage going onto the #2 ship and so on until the fleet is destroyed or until there's no more damage to be passed on. While not a perfect system, it combined with all ships firing simultaneously sped things up exponentially to the point that combat was quick and fun.
With all ships firing simultaneously though, this made keeping track of who fired what in terms of ship effectiveness against certain types impossible. So we gave each ship have a different colored die to represent their firepower, but it felt lame that every ship was identical in terms of might. Just adding more firepower to ships felt hollow because no ship was different. We wanted the ship types to feel unique, and tweaking the numbers on the dice failed to do that on a psychological level. The solution was to give each type of ship differing weapon types, and we came up with the following, which is of course subject to change.
Guns: With a mediocre chance to hit but a small potential for double damage, this basic weaponry is not terribly accurate but also has the highest potential to deal damage out of any weapon. Guns hit 50% of the time and have a 1/6 chance to deal double damage. Fighters have a 1/3 chance to dodge hits from guns and frigates have a 1/6 chance to deflect them.
Missiles: Highly accurate to the point that even fighters can't dodge them, missiles are an effective weapon. Cruisers however have anti-missile batteries that render missiles far less effective against them. Missiles hit 66% of the time and cannot be dodged. cruisers have a 1/3 chance to deflect them.
Particle Cannons: Extremely accurate and powerful weapons, particle cannons make short work of slow moving ships, but have trouble targeting fast vessels like fighters. Particle cannons hit 83% of the time but fighters have any easy time dodging them. Fighters have a 2/3 chance to dodge a particle cannon hit.
So how is each ship armed?
Fighters: 2 guns
Frigates: 1 gun and 2 missiles
Cruisers: 1 gun, 1 missile, and 3 particle cannons.
Now, the above weapons are very thematical... but very complicated. It's a tall order to get a new player to remember who hits when and when and who deflects or dodges what on what roll. We could make a complicated chart, but that would still have to be referenced constantly and slow down game-play. So rather that make a chart to explain the dice, we turned the dice into the chart itself. Designing them was a tricky intellectual challenge. How do you explain an entire rule-set on 1/2 inch pictures that can be easily interpreted at a glance? Overall I think I did well, but seeing the dice in hand already has given me ideas for improvements. For now though, they are serviceable and a LOT more fun then any previous system we've tried before. Below is a printout of the dice sheets that are in our current prototype iteration. I'd love to hear your thoughts on how they turned out.