Perhaps the most fundamental question a Ra player can ask is:
What can I expect for each of my suns?
The answer is simpler than it sounds to calculate. The bag contains 30 Ra tiles, 140 valuable tiles, and 10 disaster tiles. This means that for every Ra tile remaining in the round, you should expect 4 or 5 good tiles to be available. (Some of these tiles will not be usable due to disasters!) Divide the number of expected tiles left by the number of unspent suns and that is the number of good tiles you should expect per sun. Of course, you will hope for more--either in quality or quantity--from a powerful sun, and you will probably settle for less from a smaller sun.
And there are other considerations:
As the game goes on, the mix of tiles in the bag changes. While it is not important to count tiles exactly, you should be noticing if the Ra tiles come fast in the early rounds (a bigger payment-to-Ra ratio remains; plan to hold out for big batches) or if lots of big batches show up early (relatively more Ra tiles remain; plan to settle for less with your suns to make sure they don't go to waste).
You would like to do, not just average, better than average, so you can win rather than getting the "expected" score! This is achieved through accurate judgment of value and relative strength and astute timing of auctions. This principle is the difficult-to-grasp heart of Ra and beyond the scope of this article.
What score should I expect?
My experience is that a score of 40-50 usually takes the game. Winning scores in the 30s or even the 60s are not unheard of but somewhat rare! You start the game with 10 points but also -15 "virtual penalty points"--because you will count a civilization as a 5-point tile even though accounting-wise your score doesn't change for having it. So you will need to come up with 45-55 points over the course of the game.
What tiles are good?
Based on the above, assume that you need to accrue 50 points over the course of the game. Consider a 4-player game. Of the 140 good tiles, probably 15 will stay undrawn in the bag (because the game only goes to 27 Ra tiles) and another 25 or so will probably go to waste--disasters, left on the track, thrown away, or whatever. So your "share" of the tiles is 25 of them.
Since you need 50 points, a 2-point tile is about average and a 3-point tile is good. 5 is great, of course, but you will have few opportunities to get those!
What are specific tiles usually worth?
Gods: I consider these to be the most valuable tiles. Most often they will be traded for a flood or a civilization for 5+ points. Less frequently they will be traded for a monument in a set (also 5 points) and occasionally for a last-ditch pharaoh or upgraded to gold. To make matters even better, they allow you to reduce the value of the batch on your turn, rather than increasing it (occasionally very helpful when timing auctions) and deny the other players that tile. And in the happy case where you can buy all the tiles you want with suns, they're still worth 2 points!
Rivers/Floods: I count rivers for half a point for each round remaining in the game because to score them, you will have to fight for a flood which is only one point on its own. Of course, if you already have a flood in the current round the value rises, and if you already have many rivers, the value of a flood to you rises dramatically.
Pharaohs: In the early rounds, pharaohs are worth a lot of points. Winning pharaohs each round is worth 15 points over the course of the game, and having a big lead dissuades other players from making a concerted effort to catch you. However, the value per pharaoh declines the more pharaohs appear--and you have no way of knowing beforehand how many will show up! In the first round, I would speculatively value each pharaoh at about 2.5 points. In further rounds they are worth less as the points yet-to-be-given drop and the disparities between players become greater. (The specific value to you per pharaoh also becomes much easier to see.)
Civilizations: The first civ is worth 5 points, of course, and you should almost always try to get one. The question is, what is the second different civ worth? On the one hand, it is worth no points. On the other hand, it gives you the opportunity to get a third different civ for another 5 points and opens the potential for even more. I would value the second civ at 2 points if you have two suns left (a 3-player game, or you can get two at once) and definitely 2.5 if you have a god available. Once you have 3, of course, 4 and 5 are gravy if they show up.
A second civ of a kind is not worthless since it may provide some element of Unrest protection, but less valuable than any other non-disaster tile under most circumstances.
Monuments: A single monument is worth 1 point--unimpressive. Two of a kind are worth no more! But three are worth 6 (5 for the depth, 1 for breadth), a respectable 2 each, and five are worth 16, a very nice 3 each! If you add the bonus points for 7 or 8 points of monument breadth each monument can be worth even more.
More so than other game elements, which you can take opportunistically, monuments are most valuable with a commitment to get lots of them, to notice what is available, and to squeeze as many points as possible from depth and breadth. You will probably have to sacrifice something else--often pharaohs--to get a lot of monuments. Otherwise, you will probably pick up 3-6 monuments incidentally over the course of the game, making not much difference to your point total, possibly with an eye to picking up a 3-of-a-kind if the opportunity presents itself.
Gold: Gold is always worth 3 points, no worries, no fuss. Gold is always worth winning.
What about my suns near the end of the game?
My experience is that you should wait to decide a sun strategy until you buy your first batch. After you do, you should decide which of these categories you fall into:
I drew a good sun; I'm going to try to get two more decent ones and pick up the 5-point bonus.
I drew a good sun; I'm going to look for the best tiles I can and ignore the bonus.
I drew an OK sun; as long as I don't pick up total junk I don't need to worry about suns.
I drew a bad sun; I'm going to try to get at least one good one so I don't incur the penalty.
I drew a bad sun; I'm going to get lots of great tiles and suck up the penalty.
If you need lots of specific tiles to maximize your score--matching monuments, a flood--a strategy that doesn't focus on the suns will be necessary. If you have been playing opportunistically, taking points where they come, you might be able to eke out the winning edge by paying attention to the suns.
Credit: Karl Rainer