It is recommended that you roll 3 dice of monsters of the same type and level (i.e. Warrior-blue dice, level 2). There will be a greater chance that you can summon one of the 3 monster dice rolled.
Trap opponent
It is recommended that you make a path straight to your opponent's side. Once you have achieved this (as close as you can), expand your dungeon path to the left and right to trap your opponent and enable him to summon any monsters. All you have to do now is get to his heart points and defeat him.