You should always use the proper tools when you setup defense or attack. There are three value categories of tools:
1. Wooden tools, which can be produced consuming wood and stone. These are used by non ruby players.
2. Cheap ruby tools, which can be obtained from your workshops, but require a small amount of rubies.
3. Expensive ruby tools, which can be purchased from armorer,
The most expensive tool are the better, of course.
Defensive tools usage
The ideal is to have in every flank’s slots a 50% of each kind (ranged – melee tools). You should put tools for the gate and for the moat. This is a general setup, which will cover you at the most cases, when you are offline.
When you are on line, you should choose your tools according to what kind of defenders you will put on flanks. E.g. if you use ranged defenders, you should use Arrow_slit or Bulwark or Flaming_arrows
Keep in mind that in every wave of attack, only one defensive tool of yours is used. Also, if you have put tools on a flank, without defenders, these tools will not be used.
Offensive tools usage
Before attacking, you should spy your target, to get a report.
You can use tools on the three flanks. Each flank has a limit for allowed tools. This means that using expensive ruby tools, raises the total effectiveness of them.
You should choose tools according to what kind of defenders you will face. E.g. if the defender has bowmen, you should choose mantlets or equivalent.
On flanks with only ranged defenders, you don’t have to use scaling_ladders or equivalent.
On flanks with no defenders, you dont have to use tools.
Calculation of offensive tools
Let’s say we want to attack to a flank, which has the above data (90% wall, 138% melee protection, 136% ranged protection).
As we can see, it has 90% wall protection and a 136% defense of ranged soldiers.
We should use 9 scalling_ladders, because each one has a 10% deduction on wall protection (9 X 10% = 90%).
If we use Belfries, then we need 5 of them, because each of them has a 20% deduction on wall protection (5 X 20% = 100% > 90%).
Also, we have to use 28 mantlets (28 X 5% =140% > 136%), or 14 cast_iron_mantlets (14 X 10% = 140% > 136%), or 10 shield_walls (10 X 15% = 150% > 136%).