Expedition to the Ruins of Greyhawk is a good module that tests the party balance and the coordination between the party members.
There are many fights, with challenging and classic monsters, that will make small mistakes near fatal and fatal.
Endurance is important as many of the rewards of the module will open up only when the party is too weak to take risks and may leave treasure on the table.
As a classic module, players will need to: Know when to hold 'em, Know when to fold 'em, Know when to walk away. And know when to run.
In return, Players will get to meet the characters behind some of the spells that they may have only heard of and discover the secrets of the Multiverse!
Best for parties that can all frontline and have access to every spell list in the book! ;p