Puzzle Quest: Challenge of the Warlords

In the city of drakenburg (bottom left of the map) you can get a repeat quest called Stolen Catapult. You only go one step outside of the city to fight a catapult that is only level 20. Once you kill it, you return the quest for 200 gold and 200 exp. If you have the dwarf companion with you, he will add 10 battle skill to you for the fight. At the end of the game I was level 30 and this was the fastest way I found to boost to 50. Make sure you set the difficulty to 'easy' by changing it in the top right part of the single player menu after you hit single player on the main menu. You will get more experience by beating it faster and getting the reward over and over than you will by the 50% exp boost (which doesn't effect rewards) for playing on hard. I usually only got around 30 exp a fight anyways because it would go so quickly.

You can purchase the horn of triumph for ~400 gold which will give you another 50 exp for each time you beat the catapult. Also the Medal of Selentia that you get from a side quest will give you double exp in combat.

Any mistakes, add-ons, or issues with this guide: Please comment below and I'll change it.

The general aspect of getting this achievement is just as simple as its description, reach Level 50.

You will gain the highest amount of experience from completing side quests and fighting monsters on your travels.

It will take quite a while to get to 50, I got to 50 just before reaching Bane (the end boss) and I had completed all sidequests up to that point besides about 4 or 5.

Some additional tips to increase your exp:

-Matching purple gems in battle will give you experience points every time you match them

-You can change the difficulty to Hard, which will give you a 25% experience boost, but be careful, playing on Easy will give you a 25% decrease. Playing on Normal gives you no bonuses or hinderances; you are able to change the difficulty at any time.

-Increasing your Cunning skill will increase the experience you get from winning battles

-Divine Right Spell: You will learn this spell if you are playing as a Knight, or if you capture a Knight you can learn it from him as well. Basically this spell destroys all purple experience stars on the field, so if you find yourself with a lot of them, just pop this spell and reap the benefits. Not 100% necessary, but every little bit counts, right? :)

With those tips in mind, simply play through the game completing as many quests as possible and you should nab this towards the end of the game (even earlier if you play on Hard all the time).

Completing sidequests will also help you nab this achievement as well: