Every embarking begins from picking up a mission. These will define your object. Each mission has a different difficulty level, rewards and enemy types. All of them are generated randomly by the game thus, you will never get stuck on too hard missions.
All of the missions consist of three basic factors. These are: Mission type, required hero level and length. Mission types difine its target. It can be either killing an exact percentage of enemies or a specific enemy. It can also be an activation of some specific objects or collection of some relicts. Required level refers to the levels of your heroes as the enemies and the stress modifier will be of the same levels. The last factor corresponds to the number of camps which you will be able to partake in. The shortest missions will not let you to camp at all whilst the longest missions will enable you to camp twice a mission.
In theory, finishing a mission is not required in order to progress in the game. However, finishing one will give you rewards, heirlooms and, sometimes, trinkets which will make it easier for you. If all of your heroes die or if the player give up and retreat from a quest it will be considered as unfinished. Even though all of the find items and gold will be brought back to the town as long as there is at least one hero left alive.
Here is the list of the mission types in the Darkest Dungeon:
- Cleanse - Win 100% of the fights in the dungeon
- Explore - Explore 90% of rooms
- Kill the (Boss) - Kill X boss
- Activate - Activate 3 altars
- Gather - Collect 3 relics