One of the appeals of writing fiction is the ability of the writer to create his or her own world while paying attention to reality only as much as would facilitate the narrative. More so than in other genres, writing historical fiction requires careful attention to detail to maintain readers' willing suspension of disbelief. There are also several conventions of historical fiction to keep in mind. Depending on the specific genre of historical fiction such as historical fantasy, alternate history or period piece, historical fiction can be more difficult to write but more rewarding. An advantage could be that works set in the real world require less world-building by the author.
The setting of the work determines the amount of research necessary. Some settings, such as Nazi Germany or the Roman Republic, are widely studied and information is readily available to readers; historical inaccuracies can therefore be easily spotted. Other settings are less well-known to the average reader. Also, settings further in the past tend to have less reliable information available because of records being lost or altered over time. When writing historical fiction, the setting needs to be chosen carefully.
Adherence to clothing fashions, culture, dialogue and politics is important to the integrity of the narrative when writing historical fiction. For example, many American locations before the 1960s and 1970s had a highly conservative culture. A character with liberal views is unlikely to exist or be socially accepted during such times. This will affect plot and characterization.
Counterfactual, or alternate, history presents another common problem when writing historical fiction: the historian's fallacy. This occurs when writers treat historical figures as though they made decisions with full knowledge of the consequences. Another problem is the butterfly effect, or small changes that occur over time. The further back in history a writer sets the point of divergence into an alternate timeline, the more drastic the changes that will occur.
Fictional works that deal with war should be handled exceptionally carefully. War rarely has pure black and white morality; even the "heroic" side of a war can commit atrocities. When writing historical fiction, authors must also be careful not to oversimplify the causes of war. Instead, they should try to represent the war with a recognition of its complex network of causes and effects.
Similarly, it can be tempting to paint famous historical figures as outright heroes or villains. They should be written as people, with flaws and/or redeeming qualities. Writers should do their best to obtain speeches, photographs and other relevant data about historical figures whenever possible.