When I first reached level 20, I had 1149 energy, then it went down to 1015 the next time I logged on. Now I'm level 23 and it is only 1114. And once when I logged in at level 21, my mana was 650. Now it is 125. What's going on? Did I do something that made them lower?
Energy begins at 40 at level 1, and increases by 1 at each even-numbered level.
Mana has a base value and that value can be increased by equipment that has a +Mana value, however if you take that equipment off, your maximum mana will go back to the base value.
Press C when you are not in combat to see your Character Page. Hover your mouse over your mana to see what is boosting it, if anything. An example would be: 120 Base +170 Flamebringers Lancet +170 Heartwood Band Total: 460 Now if that character removes the Heartwood Band, the total would drop by 170 down to a new total of 290.
That explains why your mana (and though you may not have noticed, your health too) has changed as you level up and change the equipment you are wearing. Equipment only provides its bonuses while it is equipped.
If you want the prize, you have to build the ladder rung by rung. There are no shortcuts.