Salamanca is one of these games that feels uncontrollable and maybe chaotic during your first play. The disasters can move from region to region each turn making you feel that you can't prevent or escape from them and the cards rotate from one player to the next.
But after a couple of plays you will discover that Salamanca offers many hard decisions, clever tricks and more control that you thought at first.
Card management is very important, to start with. A good mix of low and high cards is the best combination.
Low number cards will usually allow you to play last and will give you an advantage: you can play/move a disaster and allow you to play an extra action.
So you can remove a disaster from your high value region, increase his size (if a proper tile is available) and immediately sell it for a larger profit, free a blocked fertile tile and then sell, increase your region value so no Conde can be placed there next turn.
In the same turn moving the disaster in an opponent's region will lower its value, allow you to place/move your Conde there or block one of his fertile tiles.
High value cards will allow you to play first (except if 5 is the smallest card) which is good if you want to move your Conde first to a good region or have first choice on available tiles.
Since played cards are rotated each turn you can block certain cards by keeping them in your hand: holding the two ruins for example will protect your buildings. Still there are two cards (no 6) that will allow a player to get one of your cards so you can't block them forever.
If you can keep track of cards as they rotate you will gain another advantage (i am not good at it!).
Tile placement is also important: you can increase your regions but you can also block opponent regions so they can no longer grow.
Fertile tiles pose another challenge: as they are removed when sold, they can split shared regions so a good trick to lower an opponent's region with a fertile tile is to build a compatible building in the same region, play first in the next turn and sell the region.
Conde placement is another thing you must be careful of: they create mini-alliances between the players as they get money when the owner also gets money from that region (income or sell). So you can help the owner but not for long as he gets more money than you.
You can even Ruin your shared building so if he sells the region your Conde will get an equal number of money!
The disasters are not so bad as they seem at first: if you build a valuable region with clever tile placement (example Monastery with Vineyards around) you will not be prevented from income each turn even if one or two disasters stay in your region. And if you attract an opponent's Conde early, he will also help you to keep your region's value over the 7 points as he will also gain income.
There are 4 different disasters and by keeping some of them in hand you prevent them from being played against you for some time.
Also you must be careful where you move the disasters: if you move the Rat for example to a region belonging to your left-hand player, he can move it back to your region next turn as he will get your just played card! If you plan to sell next turn better attack another player so you have time to sell.
Selling regions: if you can build a valuable region it is better to keep it and sell it near the end of the game as you will gain 2 income each turn plus the value of the region when you sell it. Don't wait the last turn to sell it as the disasters will land on your region!
Another tactic is to constantly grab smaller regions and sell them as soon as possible. The advantage is that because these regions are small no opponent Conde or disasters will be placed there.
There are many more tricks that you can do and many decisions to be made each turn but it will take some playings to figure them out.
Salamanca is a very tactical game and i quite enjoy it!