The following is an exert from a jury instruction used for the simple offense of driving while intoxicated:
LADIES AND GENTLEMEN OF THE JURY:
The defendant, [Defendant's Name], stands charged by information and complaint with the offense of being intoxicated while driving or operating a motor vehicle in a public place. . . .  By the term "intoxicated," as used herein, is meant not having the normal use of one's physical [or] mental faculties by reason of the introduction of [alcohol/drugs] into the body. The term "intoxicated" also means having an alcohol concentration of [0.80] or more. Paul J. McClung & Scott Carpenter, Texas Criminal Jury Charges (James Publishing ed., 1997).
Does the average juror understand this jury instruction? Will the average juror know how to apply this law to the evidence presented at trial?
Likely not, according to a laundry list of reports, academic papers, and scholars who criticize complex and confusing jury instructions. See, e.g., Walter W. Steele, Jr., and Elizabeth G. Thornburg, Jury Instructions: A Persistent Failure to Communicate, 67 N.C. L. Rev. 77, 77-105 (Detailed discussion on how complex and confusing jury instructions are not understood by jurors and how systematic flaws within the judicial system prevent clearer, more easily understood, jury instructions). The average Dallas County resident has a high school diploma, and only 28% have graduated college. Of those that graduated college, only a handful attended law school (and they will rarely ever serve as jurors). Yet, Dallas County jurors are expected to understand and apply jury instructions, many of which are immensely more complex and confusing than the simple DWI jury instructions above.
How should trial attorneys deal with this problem, assuming courts will continue to use confusing jury instructions that jurors fail to understand?
Teach. Jury instructions are full of legalese and it is up to the attorneys, or the judge, to adequately teach the legal concepts in an understandable manner to the jurors. This will typically occur during voir dire because the attorneys can engage in a conversation with the venire members, or perspective jurors. For this reason, criminal defense attorneys and prosecutors will often quibble during voir dire over what it means for someone to no longer have the normal use of mental or physical faculties. They will also battle over the meaning of beyond a reasonable doubt. For example, most Dallas and Collin County prosecutors will use a PowerPoint slide during voir dire to teach legal concepts like beyond a reasonable doubt. Specifically, they will show a picture of a nearly complete puzzle of a shark or gun. Even though pieces of the puzzle are missing, the venire members can decide the content of the puzzle as a shark or gun without a reasonable doubt.
Remind. Assuming the jurors learned the legal concepts during voir dire, the attorneys in closing argument should remind them of what they learned. This will hopefully make the law as clear as possible.
Of course, teaching and reminding the jurors of the law is an inadequate remedy since the lesson is likely jaded. The real solution is to have the judge devise simple, understandable jury instructions that any layperson with, or without, a high school diploma can comprehend and apply.