DRAGON QUEST XI: Echoes of an Elusive Age

Quests can be accepted by talking to NPCs that have a purple speech bubble above their head (also shown as a purple dot on the mini map) and accepting to take on their task. These quests are generally straightforward and will consist of defeating monsters, crafting items, talking to other NPCs or collecting items. You can track your progress in the Quest Catalogue area located in the Misc section of the main menu. There is a grand total of 60 quests in the game but they will not all be accessible to you at first. You must progress the story and reach new areas to continue unlocking them. Likewise there will be times where quests become unavailable if you haven't already completed them. This is for story reasons and after reaching Act 3 (Post Game) they will all become available again. There is no limit to how many quests you can undertake at the same time so it's best to accept all of them as you come across them in case you accidentally stumble upon the requirements to complete them in your travels.

To unlock this trophy you need to complete 40 quests. As you have a 20 quest buffer you have a lot of leeway in deciding which quests you would like to complete. Personally I would avoid any that require you to kill monsters by using a certain pep power, at least early in the game anyway, as it can be time consuming attempting to get the exact characters required pepped up at the same time and also get into a fight with the correct monster without ever losing your pepped up status in order to actually pull these off.