It is based on the legend of Tristan and Isolde, played by Christoph Waltz (in his first leading credited film role) and Antonia Preser.

Set during a raging war between Cornwall and Ireland, the film explores themes on conflict between magic and religion, violence, and destruction.

Critics praised its cinematography, for which it won an award at the 1983 Sitges Film Festival, but criticised the script, Waltz's and Preser's performances, and its interpretation of the source material.

As war rages between Cornwall and Ireland, the Cornish knight Tristan defeats Morholt, a formidable Irish warrior, in combat.

As Tristan recovers, they fall in love—even after Isolde examines his sword and deduces that he killed Morholt—and when he is called back to the Cornish court, he promises to return for her.

During his escape, Tristan crashes through and destroys a stained glass icon of Saint George, patron of England, and Marke noticeably sets aside his personal wooden cross when he is rejected by Isolde.

The characters are caught in a political war that Marke continually escalates, and even Isolde's sacrificial return to the king is not enough to end the violence.

[8] The final scene, in which Gorvenal lights a funeral pyre and cremates the lovers, emphasises the high cost of the war and is reminiscent of the film's original title, Fire and Ashes.

[9] Fürstenberg made frequent use of short, discontinuous shots; Keppler-Tasaki commented that this editing style evokes "political, social, and epistemological fragmentation".

[12] The medieval scholar Joan Tasker Grimbert wrote that Fire and Sword demonstrates the effects of economic determinism, which "individuals cannot oppose without destroying both the social order and themselves".

[8] Keppler-Tasaki similarly comments on Tristan and Isolde's rebellion against the established order, observing that it inevitably led to the breakdown of society.

[15] Christoph Waltz, who was a relatively unknown actor at the time,[16] trained in skills including stage combat and horse riding for three months in preparation for the film.

Genée recounted that the scene in which Tristan drifts out to sea after battling Morholt was a dangerous one to film due to the high surf conditions.

A reviewer for Variety praised the film's cinematography and described it as "beautifully lensed", but felt that Waltz and Preser were too inexperienced for the leading roles.

In particular, he felt that the depiction of Isolde as a witch-like femme fatale was too shallow, and that the film discarded the mythical quality of the legend.

Lacy, states that it "is distinguished by its poetic images, but it inclines to an apathy that does not do justice to the material", unlike films such as Excalibur and Perceval le Gallois (1978).