Steps to reproduce the problem:  

1)  give an AI--any AI--a negative bc credit balance.    

2)   open up the trade screen.   

3)  offer to buy any of his ships.  all of his ships.   knock yourself out.  

4)  rule the galaxy with all his ships you got for free.  

With Mercenaries installed, if you take The Anvil it more or less lets you insta-win the game. It gives you a weapon for which there is no defense. While I do enjoy trouncing the galaxy on the highest difficult levels, some would consider this an exploit.

Quoting tetleytea,

reply 2

Steps to reproduce the problem:  

1)  give an AI--any AI--a negative bc credit balance.    

2)   open up the trade screen.   

3)  offer to buy any of his ships.  all of his ships.   knock yourself out.  

4)  rule the galaxy with all his ships you got for free.  

 

Fixed.

Upgrading your survey ships takes an additional administrator which is surely wrong.  Need an upgraded Enterprise mid-game but don't want to retire Capt Kirk for Capt Picard just yet

AI will happily trade for new expensive weapon techs, but doesnt appear to use them as weapons on new ships still lower than single value of high value weapons like Disruptors / AM missiles - even when I gift them Elerium/ antimatter they don't use it but leave it in their stockpile and continue to build ships with rubbish weapons.

pse fix, been bugging me for a long time.

You mentioned, you wanted to rebalance the population to production (pop-to-prod) curve and nothing since. If you do/start this over the weekend, keep in mind, that production got buffed with crusade:
- in vanilla one point of prodcution meant 1 point was distributed between manufacturing (civil and military), research and credits
- in crusade one point of production gives one to each of the four above.
Depending on how much one values credits and the economy wheel, one can argue, that in crusade one point of production is 3 to 4 imes as strong as in vanilla. Hence, if you return to linear pop to production, I suggest using a value of .25 to .333 as multiplier in the formula, not one.
(Btw, this is also why asteroids feel so strong in crusade compared to vanilla, but I think they should be kept as is, until pop-to-prod is settled and tested by players)

Make the AI counter jamming with Accuracy increasing tech and components in their ships.

Fix attack speed (AS) stacking.
Quick-and-dirty way: change components, that grant a lot of AS, to grant % damage instead
Thorough way: I presume in the unit class there is only a stat weapon cooldown (CD) (for each type). Furthermore I presume the sum of attackspeed boosts is tracked in a variable AS at some point in the code. Then CD is modified according to: CD' = CD*(1-AS)
change this formula to CD'=CD/(1+AS)
This causes all attackspeed boosts to stack in a linear (non-divergent) way and you never again have to worry about combinations of attack speed boosts, like missile weapons research (20% AS), non-ressource booster (25% AS) and high tier booster (50% AS). If you add those up, you get: CD'=CD*(1-0,95) = CD/20, which means the weapon fires twenty times faster and missiles become the highest, range, highest attack speed and highest damage weapon type.

Arguably the above could also be applied to evasion. I presume the unit class has a variables EV (for evasion) and weapon accuracy WA (for each type). The hit probability PH is calculated by: PH = max(10% ,WA - EV).
Instead the formula should go: PH = WA/(1 + EV)

These are the most fundamental issues I see. Once pop-to-prod is settled, you should also take a look at treasure hunt. I have found it is easily the most efficient way to accumulate credits.

Happy to answer questions about my arguments above.

On some randomly generated maps, some important resources are entirely absent. This effectively hamstrings mid-tier colony developments.

This mod adds missions to fetch resources in case they are not otherwise available. I recommend this be incorporated directly into the game:

https://forums.galciv3.com/483286/Mod-Resource-Missions

Adding a vertical line that separate the 2 civilisations in the trade bar when these two have the same color will be a good thing. When you play with 70+ civilisations on the bigger map zise, it happen at every played game.

Epitheus pollen needs to be less rare. 

We need more administrators.

There are not a lot of administrator techs.

Even if the ai likes you i noticed from the turn time on techs wont give you a deal.

The krynn cleric increases 100% influence per level.

Do you really plan to start the krynn with so many administrators. 

The carbon based need to have farming to be 0.1 per turn food at some point. Otherwise the silicoln have more of an advantage.

Personally 1 think 1 point of production per person is to much cant you see if they would one half instead. 

Not liking some of the hubs. I think their to weak. They were better in the base. I really dont like getting a ship building, or a social hub with only one building. At least those two need buildings. Even going back more like two where you neededto research better as you go. 

I noticed their are no buildings for the thulium resource. There are only 2 wonders, and no buildings for the anti matter resource. There is only one wonder, and no buildings for elurim. I have seen a number of planetary resources that arent being used as resources for anything. There is no point building the kimberlies refuge if you are silicoln.

Pragmatic ideology 50 percent trade value to minors is useless if i cant trade with them. 

I heard that the aquatic trait that has no penalty is overpowered. I heard that the xenophobic trait is overpowered. Possible solution penalise colony modules more. I noticed if you customised your character, and build your colony ship it is better than the iconians can produce. Seems to be problamic with wealthy, and inventive. I heard ancient, wealthy, synthetic are also over powered. Havnt played them just heard.

Synthetic needs more ship construction techs.

Some of the events need balancing with some races like population penalties to yor. 

It would be nice like in the example of engines where if i pick an engine if you remove that choice to pick it again, so i dont waste my time picking something i already have.

In cases of mercenaries, and some colonization events instead od starting me out really powerful let me level up to it. Ie hypergate core start out with maybe 5 parsecs per turn, and maybe working up to 15 per turn after so many levels maybe based on how many turns in the game.

All these suggestions are for Crusade.

1. The Dread Lords could use a buff, they are not as dangerous as they were in GC2. Also looking in their file I see they use the old tech tree rather than the new one.

2. The UP resolution Interstellar War Fine lasts for 0 turns. Also I think we should have access to all unlocked resolutions as chairman not 3 random ones. And defying a vote should invalided the resolution but the civs that defied should just leave the UP.

3. Since the changes to minors the Malevolent trait Awe 2 is useless now.

4. The shipyard mission Treasure Hunt needs to be nerfed. Tourism and trade routes could use a boost.

5. The construction costs of Train Legion, Recruit Spy and Recruit Citizen could be reduced, while the cost of ships could be increased a little.

6. The projects Aid Economy and Aid Research could use a boost, maybe instead of a fixed reward amount they convert some social construction to which a bonus from research/wealth is added.

7. The AI doesn't use Commanders.

8. Here's a neat trick to teach the AI, you can find an opponent's colonies by following the trail of a trade route.

I made a mod to address some issues with Mercinaries. Here's the link(ed Aerie): http://www.nexusmods.com/galacticcivilizations3/mods/119/?

Here's the description:

Many mercenaries have bad combat roles. Ships with support effects set to escorts, combat ships set to support etc. This changes many of them to either capital or support. I'd have made more capital but I can't get around the rules that small and tiny ships can't be capitals.
Also, Crusade changes weapons a lot and left the old prototype weapons actually useless. Many merc ships that advertised "powerful prototype weapons" actually had the worst weapons. So I changed the power and/or the resource cost of prototypes to try and restore their old role of powerful but inefficient early-mid game weapons.

The Raptor is an interceptor.
The Nail is an assault. Also gets the correct bonus hitpoints that makes it equal to a medium ship.
The Sabre is an assault.
The Bludgeon is an assault.
The Fist of the Setting Suns is a capital.
The Elembrial is a capital.
The Praxis is a capital.
The Retribution is a capital.
Hivebase One is support.
The Viper is a capital.
The Bitte is support.
Safety In Numbers is support.
The Heptium is support.
The Gestalt is support.
The Erragis is a capital. Also it gives its kinetic damage resistance to the whole fleet as stated in its description.
The Sidrat is support.
The Compact is support.
The Straisor is support.
The Lutitia is support.
The Linked Aerie is support.
The Excruciator is a capital. Also it gets an attack and defense bonus of 25% instead of a flat 0.25 bonus.
The Fissure is a capital. Also gets the logistics reduction it was missing, and an attack bonus of 25% instead of a flat 0.25 bonus.
The Sickle gets an attack, range, and move bonus of 25% instead of a flat 0.25 bonus.
The Collective is a capital. Also gets an attack bonus of 25% instead of a flat 0.25 bonus.
The Helmder is a capital. Also its jamming bonus goes to the whole fleet as stated in its description.
The Shaout gets an attack bonus of 50% instead of a flat 0.5 bonus.
The Hermitage get and attack bonus of 25% instead of a flat 0.25 bonus.
The Cixma is a capital.
The Wraith is a capital. Also gets an attack bonus of 25% instead of a flat 0.25 bonus.
The Pewpewpewpew gets the 100 bonus hitpoints stated in its description.

The Prototype Laser now has 10 power, costs 2 elerium, and is available at Matter Disruption.
The Prototype Antimatter missile now has 16 power and costs 4 antimatter.
The Prototype Durantium Driver now costs 3 durantium instead of 12.

Feel free to make it obsolete.

It is important to limit the number of ais that can leave the united planets, so as to not invalidate the united planets.

Hey, how about a capstone tech that gives more admins?