Rise of the Tomb Raider season pass holders will get this too, by the way.
Rise of the Tomb Raider: 20 Year Celebration brings with it a couple of new adventures not found in the base edition.
The trailer above shows off both Blood Ties, a story chapter set in Croft Manor, and Lara's Nightmare, a zombie invasion experience. Both of these pieces of Rise of the Tomb Raider content will be available in the 20 Year Celebration Edition on PS4, or as part of the existing season pass for the base Xbox One and PC versions.
Rise of the Tomb Raider: 20 Year Celebration releases in October for PS4, having been available in vanilla form on PC and Xbox One.
By the way, both Rise of the Tomb Raider: 20 Year Celebration and the Season Pass include earlier DLC releases Baba Yaga: The Temple of the Witch and Cold Darkness Awakened. The new version also has some additional extras like a classic Lara skin.