For most readers, it is, at least at first, and there is no point promising otherwise. The difficulty is not in unreachable ideas but in the language and the form: Shakespeare wrote for the stage more than four hundred years ago, in an English of another age.
The Folger Shakespeare Library, which publishes the plays, points out what weighs. Some words have vanished and others have changed meaning: "affected" once meant "to be fond of," and "owes" meant "owns." Word order is often inverted, with the object before the verb, as in "Him I hit." Long interruptions separate subject from verb, words are omitted, puns carry double meanings, and metaphors are hidden. Added to this is the form: much of the dialogue is in blank verse, unrhymed iambic pentameter.
The Folger recommends reading like an actor: repeat the lines until you find their meaning, consult the dictionary, and, when a sentence stalls, regroup the words in normal English order and imagine the scene from the stage directions. For readers working with a translation, the practical advice is similar: an edition with explanatory notes at the foot of the page, one scene at a time, and then watching the play performed.
To begin, it is worth choosing a play with a plot you already know, such as Romeo and Juliet or Macbeth, and leaving Hamlet, the longest of Shakespeare's plays, for later. The aim of the first readings is to follow the story; the rest comes with repetition.
On Clavis: Romeo and Juliet, Macbeth, Hamlet.