by Derakon
I agree with Matt. Look at the investments to get food from a fireplace vs. food from the clay oven, for example.Fireplace:
* Take 2-3 clay (probably 1 action)
* Major/Minor Improvement
** Take 2-3 sheep (probably 1 action; yields 4-6 food).
Clay Oven:
* Take 3 clay (probably 1 action)
* Take at least 1 stone (1 action; may also contribute to other future purchases if you got other resources too)
** Take 1 grain
** Major/Minor Improvement (bake grain; yields 5 food) OR LATER Sow/Bake Bread (yields 5 food)
Here we're comparing 3 actions with the fireplace to 4 actions with the oven, to get roughly the same amount of food. Additionally, to repeat the process (via the ** actions) with the Fireplace you need 1 action, while the Oven requires 2. This is clearly terrible -- a food engine that yields 2.5 food/action is barely better than just going to Day Laborer over and over again.
Now of course you can sow that grain to get more of it, and then bake the proceeds instead of baking your seed grain. Then we're looking at these additional setup costs:
* Plow Field
* Sow/Bake (sow grain)
...Wait for next harvest...
* Sow/Bake (bake bread)
So in other words, in exchange for a lot of initial setup, you've gained the ability to get 5F in 1 action, once per harvest for the next three harvests. While the fireplace can just about do that from the get-go.
Now of course, as harvests come more quickly in the late game, ovens become more efficient while fireplaces become less (because of the reduced supply of animals per harvest...but the introduction of new animal types mitigates this). There's still absolutely no reason to get an oven in the early game unless you have card support for it. And even in the late game, you shouldn't go exclusively baking unless you're certain that there's lots of competition for the animals -- otherwise, you're just taking yourself out of the running for eating animals, giving lots of free food to everyone else.
One thing the Ovens are excellent for is an emergency shot of food, though. If you find yourself coming up short with a harvest on the horizon, odds are decent you can scramble up the resources you need and buy an Oven, thereby preventing your family from starving. This works precisely because baking is normally a bad strategy -- thus the actions that support it will tend to be low priorities for other players.