The “Can open project” project level right essentially gives the user access to the left menu associated with the Project tab. Consequently, the user who is granted this right will have access to…
- all tasks in the project
- the Project Documents
- the Discussion Forum
- the project Statistics
On the other hand, if you do not grant a user the “Can open project” right, the user will only be able to access assigned, to review and created tasks (if the user has sufficient Edit Task Level rights to create tasks in the project) and these will be available through the Home tab (for instance, through Home > Dashboard).