Dungeons 3: How to Beat a Diabolical Skirmish

In this guide I will explain how to complete the skirmish mode on diabolic difficulty.
the game settings are diabolic, default resources and no surprises.
The tactic will be to maximize the Arachnids and create a maze as long as possible.
The late-game Arachnids don’t do enough damage to resist the waves, so you’ll have to manage the fight along the maze, trying multiple times and weakening the enemy with each fight, until you can build the traps.

This tactic does not require a high level of skill in micro management, but you will have to design the maze carefully.

The first steps are simple, look for at least two gold veins and bring the number of snots as high as possible. When the first heroes show up, research Vortex and Arachnid, build a little Vortex and make 2 or 3 Arachnids, that’s enough.

The next step is to get to 7 Arachnids and try to conquer one or two islands of evil.
If heroes show up, immediately unlock Arcanium and Portal to return immediately.
Only two islands of evil are enough for the whole game, but having three or four is better.

You should now have enough gold for building Farm, Workshop and Arcanium. The Farm will initially have to be 6×6 and then you will have to bring it to 12×6. The Workshop will start from 3×6 and then get to 6×6, immediately build a Create-O-Mat. Arcanium will be 6×6 and then 15×6.
Deciding where to place the rooms is an important decision, because the heroes do not have to access the Workshop and even worse than the Arcanium, so you will have to dig the rooms to defend all from one side, accessible only from the Heart of the Dungeon.

Now we have to look for the maze. Join the three portals, trying to pass near the inpenetrable rock.
As soon as possible, build a Mana Shrine in the Arcanium and then another Create-O-Mat.
You will almost certainly find the two diamond veins. You have to make all three portals converge in a single point and from there create a very long maze, making it come back on itself.
Diamond veins are commonly found on opposite sides, so one will be closed behind the maze. If you run out of gold veins, research Teleportmat and Too Pitiful.

The waves of heroes continue and the Arachnids will have reached the limit of level 4, so unlock the Chamber of Relaxation and place it next to the Arcanium, 2×6 will be enough.
Increase the Arachnids to 12. Now research the Lecture Hell and create it 6×6, then research Chitin Armor.

It is important to build 4 Mana Shrines, later it will be 6 and look for Improved Mana Capacity (to be brought to 2 and then to 3). To do this we need to create the third Create-O-Mat.

We now have a lot of mana, what we need for spells. research Normal Spells, Complex Spells, and Mana Shiled. Try to assign hotkeys to Meteor Shower, Mana Shied and Demon Strength.

Now the demons will be between the sixth and eighth levels. Get ready because now it will be very hard. Waves of heroes are difficult to beat. You have to use a hit and run tactic, using Mana Shied and Demon Strength on the Arachnids and weakening enemies with Meteor Shower.
When you rest the demons, return them to Arcanium so that they create mana for the next attack.
While trying to survive this phase, get Improved Demons to 10 and get to 16 Arachnids, if you succeed you will be one step away from victory.

With 16 demons at level 10 and magical buffs you will be able to float. In the dead time build Graveyard and Sinister Laboratory, Hideout and Tinkerer’s Cave. Reasearch Crusher and Automatic Traps 2.0.
2 Goblins and 2 Banshees are enough to make the process work. Magic Room helps speed up the process. Remember to never let these monsters fight.

Fill the maze with Ice Crushers, 12 should be fine, but more is better.
Now you are safe, grab the demons and go win the game.