The realism in Ibsen's Ghosts is the easiest to find, since the author is often considered to be not just a master of the genre but the father of it. Like all Ibsen's plays, it portrays people and dialogue in a much more natural way than previous generations and ages. Before realism, literature was largely bound by the same shackles of propriety and manners that the characters in Ghosts struggle with. Ibsen was quite controversial in his time for his inclusion of topics like diseases, cheating, family secrets, and so on. In Ghosts, the author discusses these things freely and without too much guilt, with the exception of the guilt that the characters themselves feel.

Therefore, the play itself represents Realism. There are no deus ex machinas or choirs, no poignant endings, and no real solutions. The play should feel like being an invisible presence in someone's living room and seeing the true reality of people's lives, warts and all.

Symbolism comes in as early as the play's title: Ghosts. Mrs. Alving notes several times that she feels like she is living in the midst of ghosts and that she, along with everyone else, sometimes feels like a ghost as well. By that she means that her society and community cling to the past with such vehemence that it is never really allowed to die. In Ibsen's times, that was definitely the case, and even we, as today's readers, couldn't say that we have left all of it behind. Mrs. Alving, for example, has in mind the church's strong influence on people's behavior and the "proper" way of living, as well as the long memory of a small community which judges everything and everyone. In that way, people need to outlive an entire generation to become their own person and not merely a shadow/reflection of their parents. This is the core of the symbolism in Ghosts: children suffer for their parents' sins, whether straight-forwardly or symbolically. Osvald and Regina are adults, yet they're still completely bound into the drama their parents created. It's likely that it will haunt them for the rest of their lives.

Mrs. Alving and Pastor Manders also speak of what the latter considers to be foolish, sacrilegious new ideas, like couples living together without being married. This ties in with Mrs. Alving's visions of ghosts—in this case, old traditions and customs from the ages when the Bible was written are holding back people's happiness centuries, even a millennia later.

Lastly, the play has many elements of ritualism. Intertwined with the elements of symbolism, it concerns those actions of ours that we do simply because they have always been done. They're not usually questioned, but Mrs. Alving once again tells Pastor Manders that she had the courage to pull at the threads of the usual reasoning and found that there was nothing there. She seems to understand that in life, most of the rules we live by are man-made and therefore arbitrary. Yet she also admits to not having enough courage to break them.

The tragedy strikes in a non-traditional place—at people who were too passive to change something in their lives for the better. Earlier tragedy usually concerns people who have broken moral codes, because their purpose was often to be a morality tale. In this case, Mrs. Alving failed to save her son after she was convinced to keep acting like she had the happy family life despite the fact that her marriage was a failure in every sense. This can be generalized in the sense that ritualism stops people from taking the required steps to gain their freedom and happiness. Social taboos and fear of judgment keep people from doing what they know in their hearts to be right. In the end, it turns everyone into ghosts/relics of the past, reduced to actors in life's great play.

Realism is the prevailing mode of the play, with its focus on an ordinary family in an ordinary domestic setting. The action and dialogue of the characters is quite naturalistic and the play's themes are on a recognizably quotidian level, dealing with family relationships and social issues, the kind of things that affect many people in real life. Its lack of real closure, its refusal to provide a neat resolution in the manner of more traditional and conventional literature, can also be deemed realistic. Its inconclusiveness mimics real life, where so often things are not worked out, settled, and rounded off.

The play is also realistic in a more specialized sense, in relation to its particular literary historical context. It first appeared in the early 1880s, and immediately courted controversy in its depiction of such sordid facts as venereal disease. In its exploration of the grim truths that might lie behind a veneer of social respectability and problematic family relationships, it dealt unapologetically with the more sordid side of human life, which conventional and polite literature shied away from. It was a harbinger of things to come, as more and more writers began to take up the challenge of depicting the darker side of human existence.

The play also employs several instances of symbolism. The symbolism is not obtrusive - it does not disrupt the dominant mode of realism - but it is important. The central symbol is that of Oswald's illness, which is congenital syphilis, unwittingly and most irresponsibly passed on to him by his philandering father. This disease symbolizes the insidious influences of family heritage, just as the play's title refers to the lingering and pernicious influences of the past as a whole - past actions, customs, and ideas. The past continues to haunt and undermine the present. The father's legacy looms ominously over the son, while his wife has been constrained by old ideas about social respectability to maintain a facade of family honour and pride. 

The corruption of Oswald by his father, then, is both literal and metaphorical. Not only has he inherited a physical illness, he also takes after his father in his behaviour, most notably perhaps in his dalliance with the family maid, Regina, which is the direct echo of his father's flirtation with a servant many years earlier (Regina is in fact the product of this affair). 

Another example of symbolism in the play is the orphanage which Mrs Alving erects in her husband's memory. With its connotations of children who lack parental support, the orphanage takes on an ironic significance: Mr Alving did nothing worthwhile for his son.