Just saying the words “Hamlet” and “Fortinbras” might conjure up images of castles and sword fights, but it took ISU Theatre’s production of the two plays to breathe reality into these images, which they did, larger than life, last weekend.

The two plays share the same massive set and cast, and “Fortinbras” is based heavily on William Shakespeare’s “Hamlet.” But that’s where the similarities end.

“Hamlet,” for instance, was written very early in the 17th century in Elizabethan language.

It tells the story of a young man, Hamlet, who comes home from the university to find that his father has died and his mother has married his uncle.

Since “Hamlet” is one of Shakespeare’s tragedies, the ending is not exactly a happy one. And that’s where “Fortinbras” picks up — at the very end of “Hamlet.”

But while Shakespeare’s play is tragic through and through, Lee Blessing, the author of “Fortinbras,” has worked a giant yarn of humor into his play.

Upon first glance at the set of both shows, the massive castle on the Fisher stage, complete with wrap-around walkway, positively dwarfs the audience.

For the opening of “Hamlet,” the entire theater was filled with a misty haze that made me shiver.

Throughout the whole show, the set changes just a little, with perhaps the addition of a couple of chairs or a bed, with a background of wall tapestries.

The few props and simple scenery added to the starkness and feeling of loneliness of the play. It could not have been better.

Also, the use of lighting was magnificent and creative. For some scenes, the actors would be spotlighted from lights on the sides of the stage.

For others, lights emanating from grates in the floor would highlight the play’s action. But there was always a feeling of dreariness that was merely reinforced by the dim lighting.

As far as the actors go, I cannot possibly say enough good things. Tim Davis, who plays the part of Hamlet, embodies the angst, wit and grief of the character that has become known as Shakespeare’s most complex.

Davis got so into his part that he actually ripped the knee of his pants during one physical outburst.

Another stand-out includes Mark Sutch, who plays Polonius, adviser to the king and queen.

Both Sutch and Davis have the gift of expression; when either of these two men were speaking, it was easy to understand Shakespeare’s language. The dialogue was as fresh as if Lee Blessing had written it.

Patrick Wolfe, who played the part of Claudius, was the guy we all love to hate.

He carried his arrogance and regal stature just like a king. His wife Gertrude, played by Cara Peterson, was equally majestic in posture and speech; indeed, she spoke like a true queen.

Being a semi-Shakespeare buff, I was interested in some slight alterations that this particular production made to the original play.

A lot of people talk about Hamlet’s Oedipal complex, a theory that I don’t really buy. ISU Theatre, though, removed any trace of Oedipal indication.

Instead of the scene between Hamlet and Gertrude taking place on the bed of the queen’s chambers (as people may remember from Mel Gibson’s version), this show replaces the bed with a couple of chairs.

So there’s no question that Hamlet and his mom don’t have any sort of, ahem, extra-curricular relationship.

In addition, in the same scene, when Hamlet kills Polonius when the latter is hiding behind the wall tapestry, Davis does not employ just a sword, as most productions will show.

Instead, he uses a gun (with some nifty flames shooting out of it), which I think portrays the split-secondness of that decision much better than the stroke of a sword.

My only gripes are out of the control of those who are putting on the production. One is the length of the show.

While there is no way any part of the play could be cut and still maintain its message, three hours and 15 minutes is a long time to sit in a theater seat.

Another is the occasional difficulty in following the dialogue. This problem stems completely from the Elizabethan language in which Shakespeare wrote all of his plays, and it cannot be helped, save for a complete revision.

Such a drastic measure, though, would destroy the meaning of the show.

There were no such problems with “Fortinbras,” however, mostly because Blessing dispensed with the archaic language and kept the running time around two hours.

This show begins at the tail end of “Hamlet,” when the entire royal family have met untimely deaths. (I don’t mean to ruin the ending, but “Fortinbras” is based heavily on what happens at the end of Shakespeare’s play.)

Enter Fortinbras, played marvelously by Dan Fairall, the Norwegian leader who has come to Denmark to claim the throne. And once Fortinbras takes the stage, Denmark will never be the same.

Immediately, he goes about “making up the truth” about what “really” happened to the royal family (because no one would believe the truth, he said).

Once he weaves himself a complex web of falsehoods, the real fun begins. I’m talking about stuff that would’ve turned Shakespeare’s hair white (if it wasn’t already). But I’m not gonna ruin the fun for those who plan to see the show.

Fairall is a true comic genius. His part is by far the largest of any in “Fortinbras,” and after a while, the audience couldn’t help but laugh during his constant presence on stage.

While Blessing’s script might have been marginally humorous on paper, Fairall transformed it into belly-laugh fun with his facial expressions and wild gestures. In the hands of a lesser comic, the part might have gone to waste.

Lucky for us, though, Fairall and Fortinbras are one and the same, at least for a couple more weeks.

Horatio, played by Richard Dawson, is the common-sensical guy who tries to keep Fortinbras from spreading his lies.

Dawson’s frustration with Fortinbras makes him tear his hair out, but it kept the audience giggling.

Several other characters make appearances as ghosts, including Hamlet, Ophelia, Gertrude, Claudius, Polonius and Laertes. Each actor had more of an opportunity to include humor in his or her particular characters, which was a nice change of pace from the heaviness of “Hamlet.”

All in all, both shows are worth seeing, but I would recommend that if you plan on seeing one, make sure you see the other.

You’ll need a pick-you-up after “Hamlet,” but it might be a little tough to fully appreciate “Fortinbras” without knowledge of Shakespeare’s play.

This weekend “Fortinbras” runs Friday at 7:30 p.m. and Sunday at 2 p.m., while “Hamlet” is showing on Saturday at 7:30 p.m.

All shows are at Fisher Theater. Tickets are $4.75 for students and may be purchased at the door.