The Leveling Priority field (also referred to as the Priority) specifies the project's resource leveling priority relative to other projects. Leveling Priority is an integer between 0 and 1,000,000,000. A user should enter a leveling priority for every project which will be included in resource leveling before resource leveling is performed. The lower the number, the higher the priority.
The project with the highest leveling priority gets the first opportunity to use resources during resource leveling operations. If two projects need the same resource at the same time during resource leveling, the project with the higher priority gets the resource first. The default leveling priority assigned to all projects when they are created is 50.