How do Brood Clusters work?

[Gniwii]

As written it looks like the bonus provided by the Brood Cluster is a flat mod to the cost of units or is it a per turn bonus towards production?

i.e. - My city produces 34 food, are the costs of my units just 17 lower (a very minor change considering most production values) or is the cost lowered by 17 each turn (which seems very strong).

 

[dekeche]

It appears to be a flat bonus, reducing the base cost of units. So it's not a per turn boost. It's biggest advantage is in how it changes your city build; you can basically get by without building industrial exploitation, and instead concentrate on agriculture. Get a city built on the water for additional food, and you'll have a massive production discount.

 

[glorsh66]

So essentially it just a discount on production?
What is the maximum discount that you can get with this building?

 

[Sandman25DCSSS]

So essentially it just a discount on production?
What is the maximum discount that you can get with this building?

75% discount, i.e. unit will cost 25 production instead of 100.
It is really great on high production AND food colonies. You try to get equal amount of food/production (for instance, 200 production and 200 food) and put many units in queue enjoying up to 75% discount (build cheap units for that because each unit will cost 100 production (200/2) less which is huge for tier 1, but not that great for tier 3-4), then you maximize production to build as many units as possible (food is not taken into account and can be even zero when you end turn). It is one of the most powerful buildings in the game, especially if you are lucky to get production from happiness event.