So, first off, this is the scrolls hex board. We're going to talk about the importance of unit placement and defending your idols.
You will always see your units on the left, and your opponent on the right (your opponent will see a mirror of the board). Each side has five idols. You win the game by destroying 3 of the five idols. What this means is that you only need
THREE of your idols to stay alive to stay in the game. You don't have to defend the whole board. Because of this, you'll want to defend three lanes, keeping them adjacent to each other so that your forces can easily move between them without getting seperated.
The center lane is the strongest lane in the game to control. If you can control the center and force the enemy out of it, you're forcing them to split their forces to either side to continue. If you can destroy the enemy's center idol, it becomes significantly harder for them to come back, especially if you can maintain control of your chosen three lanes. Because of this, your defenses should look like any of the following.
Or the top three rows (I'm too lazy to make another image). What you want to force your enemy to do, and what you want to avoid, is something like this.
Other important things to note that screenshots would probably help a lot is to make sure you put structures in the front of your lanes, so that your attacking units can be protected behind them. Even attacking structures, such as lobbers, are usually best placed up front (which would force them to attack your enemy's back row) so that their high hp can help protect your more important attacking units behind them.
So, now you know what lanes you're going to be defending, but where do you place your units? It's round one, you've sacrificed for one resource, and you have a creature in hand that you can place. Where do you want to put it? Here.
Each unit (with exception of structures) has a movement of one. This means that every turn, they can move one hex space. By placing your starting unit here, you put pressure on the all important center lane, and give your unit the maximum number of possible spaces to move to should it need to.
While the main objective is to destroy your enemy's idols, your primary goal should be to take out their units. They are what pose a threat to you the most, the idols can usually wait. Most units also have a cooldown of 2, so by placing your starting unit here, it can reach any other unit your opponent might put down before its cooldown comes up.
The only place your opponent can place a unit that yours won't be able to reach is on the top or bottom rows (which we've already established to be the weakest.) If he plays one there immediately after yours, your unit can move to intercept in the next turn.
By moving your unit up, it gives the enemy unit no place to escape to. They can either stay in the top lane, which you will be able to move to and attack on the next round, or move down, in which case your unit is already positioned to attack.
Of course, different decks are going to have different counters for all of these. If your opponent places a structure in front of his unit, don't engage it. Focus on keeping control of the center, and try to place your own structure to counter and give you defense. Practice practice practice, and you'll get a feel for when to use spells, when to avoid fights, when to attack, etc etc. But never forget that units can move, and always keep possible movements in mind while playing.
That's it for the first installment!