Rules for Feudal Endeavor - Would appreciate some critique

You might want to consult with a historian specializing on the Russian history to fix your "Families of Imperial Russia" page.

I`m also confused as to why there are 12th century European "knights" in a game about 18th century imperial Russia. ;)

Table of Contents: "cossack" should be capitalized

Page 1: I recommend not justifying the text, especially when the columns are so narrow. Just make it left or center aligned. It looks especially ugly in places on the Romanov and Lomanosov paragraphs.

Page 3: I like this page. At first I didn't like the redundant symbology explanations (especially the doubled white "Gain 1 Knight"), but on second thought it is simple, easy to use when looking up effects, and unambiguous.

Page 4: So the bidding area is at the top of the board, and is hidden behind the screen? This and the setup diagram suggest that the Bidding Screen is in front of their board, which means the entire board is hidden (or at least obscured) from view. Why not just say "place the bidding screen in front of your board"?

Page 6: In the diagram, you should put some arrows to make explicit which parts of the tile are being indicated; in part because of the thick tile border, it takes a moment to figure out the "Spend" refers to the stuff on the left of the black arrow (and "Gain" to the stuff on the right), and especially to figure out that "Resources that may be used to be" refers to the icons in the tiny banner. A simple arrow pointing from each descriptor to the appropriate part of the tile would help a lot.

Page 8: Ok, so it looks like the bidding screen is not always in front of the player board (as I had thought from the setup description). Since the bidding screen is only in front of the player board during bidding, I suggest removing that instruction from the setup section to make it seem less permanent (you already instruct the player to place it in front of the player board on page 6).

Page 8: The text is suddenly justified again, which is a little distracting (especially in the final paragraph). I recommend no justified text.

Page 8: The bullet points seem out of place. Maybe use numbers? Or maybe they are too large.

Page 8: "beginning with the deed in the #1 auction locations and continuing to the right" - there is only one #1 auction space (as far as I can tell), so "locations" should not be plural.

Page 9: You have an extra period after the exclamation mark ("for additional scoring opportunities!.")

Page 10: I assume that the player cannot choose to both fulfill a bidding card and place a brick (based on the "bonus Palace Tithing action rule); either way, you should clarify this.

Page 10: Bolded statement("Beginning with...Palace Renovation Tithing") is another instance of distractingly justified text. Going to stop talking about this now.

Page 12: In part 2, you are missing a space between the 1-laurels and the left parenthesis ("1 O(up to a maximum...", where 0 is the laurels) and between the 8-laurels and the per ("8 0per Political...")

Page 12: In part 5, are the bonuses cumulative? That is, can you use (e.g.) a serf in both a set of 3 serfs AND a set of serf-horse-knight? Something to clarify.

Page 12: In part 6, the minus sign (-0) is easy to miss. On a more general note, this mechanic is generally confusing because some of the spaces give stuff when you place a tile on them and others do something bad when you don't place a tile on them. I understand why you do this (to avoid having to track points during the game), but it is still not intuitive. Perhaps you could at least use a different symbol for negative points than for positive points? Alternately, if you are willing to add a victory track or point tokens, you could equivalently make the VP rewards positive (though I'm sure you have already tried that given how the negative points work).

There were no knights in 18th century Russia. (Nor anywhere in the world by that point).
The entire concept is thematically out of place.

You may want to use a word "Nobles" instead.

My bet is that it's all hastily copied from Wikipedia and mixed-up in the process.

It does. There are mistakes. Like, big ones.

For example this:

"Catherine the Great was born to the Petrovna family as Elizabeth in 1709"

This is not just wrong, but a complete nonsense.

1. Catherine and Elizabeth are two different people.
2. Petrovna is not a family name. It's a patronymic. Elizabeth's father was Peter the Great, hence she is Elizaveta Petrovna Romanova.
3. Catherine's original name was Sophie of Anhalt-Zerbst. She was a German princess. She took the name and patronymic Ekaterina Alekseevna when she converted to Eastern Orthodoxy.
4. She should belong to Romanov family name.
5. Catherine was born in 1729, not 1709. It's Elizabeth who was born in 1709.

Like I said, you need a historian to look through your stuff.
Or drop the "Imperial Russia" theme and just use generic fantasy setting.

Definitely.