Dragon Age 3 Inquisition storyline and world events are affected by the historical events from Dragon Age Origins and Dragon Age 2. It has been confirmed that reshaping the world of DAI would be based on import saves, pre-built histories or customisable default canon.
Using Import Saves
Using import saves from Dragon Age Origins and Dragon Age 2 would be the most commonly way to reshape Dragon Age Inquisition for loyal players who completed both previous games.
However, import saves feature consequences depending on the choices made on previous game series. As an example, the world of Dragon Age Inquisition may live with the Queen of Fereldan if Anora rules in Dragon Age Origins instead of Alistair or notes may contain that the Champion of Kirkwall ruled as a viscount if sided with Templars before leaving the city during the finale in Dragon Age 2.
Essentially, imported save contents will also influence certain secondary or side quests in the game such as "Finding Nathaniel" quest if spared by the Warden in Dragon Age Origins and "Last of His Line" quest if Bhelen becomes the ruler of Orzammar instead of Harrowmont.
For those players who haven't played or completed Dragon Age Origins or Dragon Age 2, an option to choose on pre-built history or default canon will appear to set the events in Dragon Age Inquisition in motion. These defaults are similar to import saves except they feature logical ideals from previous game series.
In Dragon Age 2, there are three primary pre-built histories for players to use and certain quests may become available appropriate to the chosen historical line. If using "Hero of Fereldan", the Warden lives and will be mentioned by Bodahn when spoken to for the first time.
"Martyr" pre-built history activates the "Last of His Line" and "Finding Nathaniel" quests in act 1 and act 3, respectively. If "No Compromise" has been chosen, Anora will rule Fereldan and Alistair would be found at The Hanged Man tavern in act 1 and act 2 as a drunken patron after the defeat of the Archdemon.
Dragon Age Keep
BioWare already launched the Dragon Keep Web site which is an official mod-like service to create logical saves from Dragon Age Origins and Dragon Age 2 for Dragon Age Inquisition to use in addition to pre-built histories.
"On August 28 2013, it was announced that players will be able to create a their own specific canon and customise all important decisions from previous games in a cloud-based system called Dragon Age Keep. This new system will also solve plot logic issues that occurred when importing save-games in previous titles," posted by Nexus Mod member CyrusFyre.
Dragon Age Keep allow players to manually modify world-states and events during Dragon Age Origins and Dragon Age 2 without suffering from import bugs or issues by enabling the cloud service to fix logical ideals of those events.
In this way, players can create their own version of "default canon" apart from what BioWare use and pre-built histories. Visit the official Dragon Age Keep Web site and sign in a valid Origins account to know more.