I have reached level 532 and gained 1,6802,800 score. Dmg 8924 (2340+6584), critical 1845 (75+1770), health 10654 (4575+6079) and 12860 armour is my character's states. I basically build enough armour level and life when my character only takes minimum damages from any monsters; then increase my attack power. Every level adds extra dmg of monsters;therefore you may have to earn more armour rating and life to prepare for next levels, even if your character has just reached minimum dmg of monsters.
Our attack power is very important but options of higher armour rating have to be based on survival during our game play. When a lot of archers or wizards appear, you cannot avoid many range attacks during your fighting. Under the situation, higher armour rating will save us.
If you wanted to reach higher level of bit dungeon, I would suggest choose armour options on your shoes instead of a speed option. Because of a lack of armour rating, you may have to drop a lot of critical options or strong equipment through this game.
Proc* damage is that 'your current armour / 2 and round down to current 1. proc* attack'. In other words, 0.5 value is ignored after the a mathematical formula.
2. Your normal attach damage, critical damage and health value cannot increase or change your proc* damage.
For example, if your avatar has 1000 armour, your proc* attack will be 500. if the character has 1001 armour, the proc* will be also 500 because 500.5 damage hit is considered as same as 500 attack.