It looks like you unlock Adventure Mode when you finish the storyline.
Nice, they actually used at least one idea I mentioned when I wrote up this open world/free roam proposal awhile ago….
And it looks like a change in difficulty settings based on the following:
- SliderText – Increase Difficulty by using the slider below.
- DifficultySelector_Description_0 – At this difficulty enemies are weaker and have less health.
- DifficultySelector_Description_1 – This is the baseline Diablo III experience.
- DifficultySelector_Description_2 – Enemies are slightly more powerful and have a little more health.
- DifficultySelector_Description_3 – Enemies are more powerful and have more health. There is also an increase to experience and item drops.
- DifficultySelector_Description_4 – Enemies are more powerful and have more health. There is also an increase to experience and item drops.
- DifficultySelector_Description_5 – Enemies are much more powerful and are very difficult to kill. There is also a significant increase to experience and item drops..