Orymus3

Then allow ships to fly anywhere but if not within supply base range they get -50%penalty to damage (or tactics or whatever).

This is what I call an artificial rule. I generally try to refrain from using these arbitrary rules. These are rules that, while they allow to fill in an objective, don't fit organically in the design. In other words, the player wouldn't guess this outcome unless he was told about it through in-game messaging. As a counter-example, if the fuel/fuel tanks was a modifier to ship armor and damage, players would understand indirectly that, the further they get from home, the more vulnerable their ships would become. There wouldn't be a specific distance or specific value that would kick in and could be easily forgotten about and come back to bit the player in the ass: everything would be clear from the start and the player would understand that its part of the game economy and that he'd have to gauge his moves accordingly.

Now, I won't actually implement this system as its silly (I don't see how it could make sense to the player anyway) but it would be a more organic method to implement such a system.

Then don't allow/discourage taking a lot of fuel It's your game and your rules, you don't like something, don't allow it

Interesting you should mention that. Currently, fuel consumed per unit of time is based on ship mass, and ship mass encompasses fuel tanks. Thus, the more fuel you have, the further or faster you can go, but insodoing, the more fuel it costs. In the end, there is an advantage in bringing more fuel, but a portion of this advantage translates into burning a lot more fuel resources. From an economic macro standpoint, its a bad move, but the tactical/strategic advantage of grabbing a few planets is too dire a consequence.

Besides, I'm really interested in adding a layer of strategy to the game, and a defensive aspect would be necessary.

For example, a lot of medieval games use 'walls' and a lot don't. I generally like those that do because they allow you to craft a part of the landscape to suit your need. They give the player an opportunity to be creative about what they'll do (create a trap? give an incentive for the player to more through a specific choke? slow them down exactly where you need them to be?, etc).

Playing with ships is fun, but I'd really like to throw them another bone, a game ingredient/toy the players can use to mess with one another.

What if sensors/communications were a key part of the game? If your sensors are disrupted then you lose detailed information on what is going on in a region. Life on the planet would still continue, and they would carry on as they were, but if an enemy fleet with suitable jamming equipment got in range they could black out part of your map and allow a fleet to move without you knowing exact details.

Its actually part of the plan. I've got one of the races using a radar jammer sort of ship. In additional, planetary sensors are often found as satellites, and if broken, will be reduced in efficiency, rendering the player 'blind' to certain areas of his empire. That said, this is an offensive strategy, not a defensive one. I like the strategic layer it adds (there are specific targets you want to disrupt in order to come in blindly, or you can feign at attack by eliminating a few satellites and attack the other front instead), but it does not provide a means to defend oneself from the enemy though.

Combine that with the long duration battles to actually conquer planets, and it gives a viable defensive measures with attack counters:

I'm affraid I'm missing the part where there's an inclusion of an efficient defensive strategy here. Wouldn't the player play cat and mouse with his opponent, not knowing where to hunt them down?

Of course, relying on building a fleet of jammers means you give up resources that could have gone towards your attacking fleet, which puts you at risk of being clobbered that much easier if you run into the opposing battle fleet.

So essentially, you are taxing the attacker with the need to build radar jammers which are inefficient combat ships. That's also a side objective I'm currently pursuing. I've also included the need to resupply (ordnance, missiles, fuel) in such a way where the defender is always at an advantage (he is much closer to his bases). That said, it mostly means attrition of the attacking forces, but assuming he's waited for a critical mass, there still wouldn't be an efficient way for the player to have prepared for the defense. If you don't know where the enemy will strike, or if he chose to run by your forces and go straight for the heart of the empire, there will be little you'll be able to leave behind to counter this, and that's what I'm really after (the thing you can leave behind around important clusters when your fleet needs to be someplace else).

Area control and surprises. What if fleets weren't always easy to see, especially for attackers? Set up sensor girds to better detect vessels entering your region of space, so the defender has the advantage of knowledge.

Yes, there are recon vessels/scouts (even some cloaked) already planned. When I mean the enemy fleet runs past your fleet for a planet, I also mean they know what they are attacking, which inherently means they've scouted it before or are doing it currently. First rule of engagement dictates you need to have recon first.

Use some kind of webbing mechanic to allow a smaller fleet to delay a larger one,

How would this work exactly? This is much closer to the mechanic I'm trying to define, but it still sounds vague. I'm trying to get a concrete mechanic in place that does precisely that.

It could be building specific ships, as you seem to imply, whose purpose would be to slow down the enemy (VGA Planets uses minelaying ships in this manner) or it could be something else altogether. Also, slowing might not be sufficient. The threat of perhaps eliminating a few of your enemies is also important as it could really shift the battle in the defender's favor, forcing a retreat, or allowing the defender to trap his opponent and take a big win. There's little in life that's as satisfying as designing a trap (thinking about what the opponent will do, etc.) and seeing it succeed. It requires an investment of some kind (minerals, money, time, etc) and may yield favorable results (or not).

So in theory, what you're proposing works, I just need something more practical.

I may disappoint but I wasn't planning on going with alien races (just alien animals and such) at least not to begin with, I thought I'd resign that to possible future expansion

There's nothing disappointing about limiting your scope. If anything, its a good production habit, and it leaves you much room for later content addition without cutting back on making a fun core gameplay.

- range, each fleet can not fly too far from their planets (bases) which makes a strike inside enemy territory impossible (without conquering some depots first)

This sort of loops back to the initial implementation of "communication ranges" I had in mind, and I chose against doing this. In the end, I want the players to be able to send scout ships very far from their home. It is an investment they make to have better information, at the expanse of having ships outside of their empire which can neither contribute to economy or defense. The tradeoff is sufficient so that players don't need to be hassled with an additionnal artificial mechanic that prevents them from making mistakes and crafty plays. (imo)

- fuel "This goes on until either of you no longer has any fuel", this is not actually that bad, the defender has an easy near supply of fuel, the attacker don't, therefore such run is not viable (and if both fleets run out of fuel, then it's the loss of attacker since the defender can send one measly scout ship and incinerate the whole immobilized invading fleet )

Yes and no. An invader with a lot of fuel and superior engines would just make this linger for a while, taking 10 players or more. Then the defender would either need to give chase to the ship only (allowing the player to grow the planets) or split the fleet between retaking the planets (slowing down) up to the point where he no longer has enough ships nearby to give pursuit (each ship would take one turn to reclaim each of the planets).

Don't get me wrong, I see Blitzkrieg as a potential successful strategy, but only against a player with a frail defense that has chosen to focus on a mobile fleet. Having a defensive mechanic is only meant to give the players an option to slow down shock strategies should the need arise, and enrich the general strategy aspect of the game.

Some species will be naturally better at Blitz, and others slower in general, and I don't want to make this type encounter unbearable for the slower species.

Generally, it depends on how much turtling you want to allow in your game.

Some. I want the player to feel its worth investing in their colonies, thus, they're able to hold them for a while. I also want the idea of a sphere of influence, where the players take several planets and deny enemy traffic in-between these. Ideally, enemy ships (aside from dedicated efforts) should not easily pierce through defenses and enter the periphery of your space. You won't want them to see what's happening.

An alternative I've been thinking about it allowing some of the planets to have ranged attacks of their own. For example, if an enemy ship comes within a certain distance, they could launch a squadron of fighters or fire a planetary canon at them, possibly damaging the ship. The problem is that this increases the area of influence of the planet only, but does not necessarily affect the general space geography per se.

The advantage of minefields was that you could lay them where you'd expect the enemy to go through (and not necessarily along the entire frontline). It required the opponent to committ to a strategy before being at risk, and it still gave them the option to go slowly/more carefully to avoid the damage. Having ranged attacks from planets would not allow players the option to avoid the dmg, and would increase turtling in a way that could prevent crafty intrusions.

You can just have a mine

I'm trying to find a different approach here, and I don't have much of a better reason than to do differently than my reference model. I want to build a different strategic challenge for the players, and I feel that it calls for a different mechanic altogether.

a mine always disable the (warp)engine of an(one, not the fleet) enemy ship for one turn

VGA Planets also had the Webmines which would drain ships from their fuel without doing dmg. In the end, you'd have a bunch of disabled ships caught in the field and this was interesting, but made play linger.

The problem with your solution is that it will slow down the enemy, but you're not giving them any incentive to sweep the mines (they'll lose time both ways). They'll just fire through anywhere, and not worry about the consequences. The interesting aspect about mines is that you don't know if there are any, and you choose to either be careful or risk it. In this case, the only risk you take is being delayed a few turns.

The part I agree with though is that mines should explode and disappear. In VGA Planets, they did, but you had thousands of them at any given place, and as mines fired, it only very gradually decrease the AoE of your minefield, in such a way that the only efficient way to go through was sweeping.

Overall, I feel I need to move to a different concept than mines. From a macro perspective, how would you defend your sphere of influence in space (aside from with mines)?

I've also thought about putting satellites in orbit of planets you don't control, but then, why wouldn't you want to control the planet if you could reach it and put a satellite? Plus, the satellite didn't do much good aside from relaying information for you.

I've been tinkering with the idea of putting Starbases in deep space too, but I'm guessing they'd make more sens orbiting a planet than wander deep space.

Oh, reproduction is the most important, biologically humans mainly enjoy power to increase their reproduction-chances;

bastard-children would be plentifull, and could potentially be put in places of high power, or just be left to take their own chance,

official offspring would have to be protected and made ready to fullfill the role of emperor.

Hate to say this, but one of the major differences between a king and an emperor is that the emperor is not hereditary: it is based on merit and bestowed by a third party (often a religious power).

Having children is thus rather pointless, more often than not, emperors that attempted to pass their powers to their sons created a revolution.

In an empire, the emperor tends to be middle-aged to old as succession is rarely won by a young unproven fellow...

Clever!

Also, would you say the outline is black? I've always been wondering whether I should use pitch black, or some kind of a dark tone that fits with the overall character design?