Credit goes to Kevin Bourrillion from BGG for this article:
There's an appalling lack of strategy advice for this game. I thought I'd throw some tips out there and see if they do anyone any good. Disclaimer: I ain't no world champion. Far from it, in fact. I may try to sound like a know-it-all here, but really, you have to judge for yourself whether each of my tips is any good or not.
So with that out of the way...
WHAT IS IT WORTH?
This may seem painfully obvious, but unfortunately to many players it is not. Before you bid, take a second to think to yourself, "what actually *happens* if I win?" For example -- will it put you out of the round? (Without a civ?) Will it leave you with the lowest suns left on the table? Or with a gigantic gap in your suns, practically guaranteeing future distress? Sure, this meager lot in front of you might be "worth my 3", but if you call Ra and win it, and now your lowest sun is a 9, what future bargain opportunity might you have just lost?
Many times thinking like this won't actually change your mind, but still, it's a better way to evaluate your choice than just a naive assessment of "how much is this lot worth?"
THE VALUE OF THE SUNS
I see many decisions getting made on reasoning like, "this lot isn't great but it's obviously worth a 2", or "I really want this but 12 is just too expensive." Intuitively we think of the suns as being like money -- we think of the 10 sun as being worth about two of the 5 sun. However, this is bunk. Try relabeling your suns 1,000,001, 1,000,002 up through 1,000,016. Now you've all but eliminated this perceived relation between perceived values -- yet you haven't change the game a single bit. This should tell you something.
Always keep an eye on what proportion of your suns are depleted vs. what proportion of the Ra spaces are filled. If you let the former get too far ahead of the latter, you risk going out of the round early (or passing up great auctions for fear of going out early). Conversely, if the Ra track gets too far ahead, you risk closing the epoch with leftover face-up suns that earned you nothing.
OF NILES AND PHARAOHS
The earlier the epoch, the more valuable they can be. A large pharaoh win in epoch 3 might net you 5 points, but a large pharaoh win in epoch 1 could end up yielding 10 or 15 by game's end.
OF FLOODS AND CIVS
Just at the end of an epoch, before all the tiles go flying back into the box, take a quick look around the table. How many floods and civilizations do you see? In a stastically average epoch, you might expect to see maybe about 3 and 6, respectively. If you can make a quick mental note when you notice *significantly* more or less than this amount, then this knowledge may help you to reason more accurately about your decisions in future epochs. This is not an exact figure, just a very rough rule of thumb.
Naively, any tile worth 3 points or more to you is worth exchanging your god tile for. But this is an oversimplification. Consider two things: how likely is it that you will be able to take this lot in an auction, or a future lot also containing this desired tile? Second, how likely is it that you will get another chance to use your god tile which will be more lucrative still than this one? Check your suns and the open Ra spaces, and if these are many, you might want to hold out for something better.
When a disaster comes up that doesn't apply to any of the tiles you've already won, but would cause damage to any of your opponents, your palms should start sweating. A lot like this can sometimes be a fantastic bargain, since its value to your opponents is lessened.
THAT SUN IN THE MIDDLE
In epochs 1 and 2, that sun in the middle of the board has real value. I wish I had a nickel for every time I won an auction, smugly raked in my tiles and then stopped short saying, "oh. shit. I've got the f--ing ONE sun for next round now!" ... don't forget to always pay attention to what's there; it's as much a part of the auction block as the tiles are.
In epoch 3 things are, of course, different. I think of the 5 point adjustment at the end of the game as being a little "consolation prize" or "penalty" that it's hard to really have much direct control over. I wouldn't guide your bids very strongly by your desire to get the +5 or avoid the -5; it's just too unpredictable.
WHEN TO INVOKE RA
Whenever, on your turn, the current lot is one that you would be happy to win with your lowest-valued sun, you should consider invoking Ra. If you opt to draw instead, you are very likely to be increasing the value of the lot, so you're essentially placing a wager that (a) you will be able to win the eventual auction (so that your draw does not enrich your opponents), and (b) when you do win it, it will be a more advantageous exchange for you than the currently offered one.
You can also invoke Ra offensively; suppose your opponent has eleven rivers, no flood, and a god tile, and a flood is up on the block. Invoking Ra might just keep the flood out of his hands. But that leads me to....
Sometimes you're tempted to make a choice based not on how it helps you but on how it hurts another player. In a three-player game this might be a sound practice, but it's unlikely to be worthwhile with 4 or 5. I suppose if you are really quick on your feet and can determine that player X is in the lead, and that you are in second place, so hurting player X directly increases your own chances of victory -- well, go right ahead. Most times though I just grunt in disgust and let them have their goddamn fifth civ or what-have-you and get over it.
The same could be said of the practice of overbidding for a lot in an attempt to force your opponent to pay top dollar. Ask yourself if it's really worth the risk of backfire. (Of course, if you'd like to bid 4, but also have the 6, and your opponent has the 5 and 13, by all means overbid! Duh!) :-)
WHICH MONUMENT TO KILL?
If you take an Earthquake, it can be agonizing to choose which of your monuments (your babies, your hopes and dreams!) to discard. Clearly you should be looking at your two-of-a-kinds first, since one tile in each two-of-a-kind is currently worthless to you. If you're lucky, you'll have several of these to choose between. But which to choose? Look for the two monument types that your opponents possess the *most* of (or include discarded monuments in this total, if you're *really* paying attention!). You're unlikely to make these into three-of-a-kinds (both because there are fewer remaining and due to increased competition for those that do remain), so your second copy is doing nothing for you. Pitch them.
On the other hand, if you have to discard a monument you have only one of, you probably want to discard the one that your opponents have the *fewest* of. There will be more copies of it left, and possibly less
competition for those copies as well (debatable).