My tactics (useful specially for noobs)

[Slichizard]

^This is where CTA spell kicks in. At early level bile demons are still obedient and are effective as trolls. Just make sure your warlocks research CTA spell, cast it and then you can force your creatures train/research/build non-stop.

[Ballwinkle]

He played me before he posted it. He was one of the best i have played, although i still beat him :P

[seang]

i have lost 2 times. (played 8-10 times) One when played 1x1, one 2x2. Ballwinkle, we played 1x1?

1. omg surprise when i left 2 squares of ground between my land and rock at left side of map. Opponent digged through it unnoticed and came right to heart of my dungeon. Surpriiiiiiseeeee)
That is how advice #3 appeared)

2. There were 2 battles. I won first battle in centre of map, imprisoned and turned on my side about 1\3 enemies creatures. After that i relaxed and switched off awareness. I attacked fast (without converting land to my color) through tight corridor with many zigzags. Enemies summoned Horny 3 times. I completely forget about Heal and relaxed. At the end 2\3 army was lost and i surrendered.
- when you attacking, use imps to get rid of walls on your way - it is very important

DK2 amazing game with huge amount of tactics...

[Slichizard]

^And here's another advice : Do not convert enemy creatures. Just keep healing them so your opponent wont be able to get new ones. Convert only if creature's level is above 6.

[seang]

Adding to #2:
to hold positions and fall back enemys imps, use cannons
place cannons near strategy place as early as you can, and dig off land around them. Dont build too many, because each shot drains your mana.
(if enemy bulit many cannons in one place, you can low his mana to zero by throwing&grabbing creature near cannons)

with this tactic you can get 3 portals on map with 4 portals

[Duke Ragereaver]

Better to use lightning traps instead of cannons, they are superior because they never miss and can do some decent instant damage.