Timeline Theories/Split Timeline Disciplines

The Split Timeline Disciplines are rudimentary guidelines followed and supported by splittists, fans who believe in an overall split timeline chronology in the Zelda series, beginning with Skyward Sword and Ocarina of Time. After Ocarina of Time, the timeline may follow one of two common, equally significant paths: the 2D Child Order or the 2D Adult Order. Both arrays work off of Ocarina of Time ' s dual ending, in the child era and adult era of Link's life. Once developer confirmations confirmed the placement of Twilight Princess, the two disciplines gained credibility, and yet gained further ambiguity.

2D Child Timeline
The "2D Child" Timeline is a discipline of the Split Timeline that proposes that all of the older (2D) titles are to be placed in the Child Timeline, along with Majora's Mask and Twilight Princess; the Adult Timeline serves as a separate story apart from the older games and thus completely free to continue into its own chronology.

Since many split timeline theorists placed the 2D games in the Child Timeline prior to the split's confirmation, many of them continued to do so after TP's release.   (NOTE: The Oracles placement is debatable and irrelevant to this issue, and the same is true for the placement of TMC. For reference purposes, most theorists place the Oracle games either after ALttP/LA or after LoZ/AoL, and most place TMC either before OoT or immediately before FS/FSA.)

Strengths of the 2D Child order

 * There are significant similarities between TP and ALttP.
 * The resting place of the Master Sword in ALttP is accounted for in TP, and TP appears to bridge OoT and ALttP's Master Sword locations.

Weaknesses of the 2D Child order

 * No documented existence of a sages' seal on the Sacred Realm in the Child timeline, and this must be speculated as a separate event.
 * There is no cohesiveness regarding the state of the Triforce between TP and ALttP.

2D Adult Timeline
The “2D Adult" Timeline is a discipline of the Split Timeline that proposes that all of the older (2D) titles are to be placed in the Adult Timeline, along with The Wind Waker and Phantom Hourglass, and that the Child Timeline serves as a separate story apart from the older games and thus completely free to continue into its own chronology.

Since most linearists placed these games after TWW/PH anyway, many linearists decided immediately on this order when they began to adopt Split Timelines after the confirmation.

  (NOTE: The Oracles placement is debatable and irrelevant to this issue, and the same is true for the placement of TMC. For reference purposes, most theorists place the Oracle games either after ALttP/LA or after LoZ/AoL, and most place TMC either before OoT or immediately before FS/FSA.)

Strengths of the 2D Adult order

 * There is documented existence of a sages' seal on the Sacred Realm in the Adult timeline.
 * The state of the Triforce appears to be consistent between TWW and ALttP, assuming the Triforce returns to the Sacred Realm.
 * The new Hyrule featured in ST bares many similarities with FS and FSA, in terms of elements and geography.

Weaknesses of the 2D Adult order

 * The resting place of the Master Sword in ALttP is unaccounted for in TWW.
 * The sages' seal on the Sacred Realm in OoT may be difficult to connect to ALttP because Ganon from OoT is defeated in TWW, so a new seal and Ganon would have to exist (and Ganon would need to enter the SR again) for ALttP's backstory to occur, which would make the original OoT connection redundant.
 * In ST a new Hyrule was introduced, where the Triforce and the Golden Goddesses do not appear to play any role in people's minds, instead being replaced by the Spirits of Good.
 * TWW's ending, and the new Hyrule of ST, indicate that no games that take place in the original Hyrule will occur after TWW, due to its destruction. This conflicts with the fact that ALttP's Hyrule is extremely similar in history, geography/landmarks and many other features, to OoT's Hyrule. This includes the Master Sword lost at the bottom of the ocean, and the Sacred Realm (and Triforce) that was linked to the old Hyrule.
 * ALttP displays a fully fleshed out history of Hyrule, as opposed to TWW where the legends of Hyrule are fading away.
 * Sometime between OoT and TWW the Gorons moved away from Death Mountain. This is clear as they are not present at Dragon Roost Island (which is commonly thought to be Death Mountain due to the widespread presence of Bomb Flowers and due to the presence of a mural of what appears to be Volvagia at the entrance of Dragon Roost Cavern) during TWW. In PH, it is clear that they moved to a land that would become Goron Island and Dee Ess Island in the World of the Ocean King. As a result of this no game following TWW should have Gorons at Death Mountain. In ST's New Hyrule, Gorons live in an unnamed mountain. Although it is not impossible that the mountain could be named "Death Mountain" in the future, it also seems unlikely, since it could remain unnamed or take a different name. It is not clear if these Gorons are related to the Gorons of PH.