Shadow the Hedgehog Secret Doors tiering.
How useful each door in each level is. The first tier are doors that are always used. The second tier are useful as well but not on all paths. The last are doors that should be always skipped because the contents are either too niche and can be substituted or are completely useless to the player.
Credit to https://sonic.fandom.com/wiki/Category:Shadow_the_Hedgehog_stages for the images.
