Most states have adopted pattern jury instructions, also known as standard, model, or uniform instructions, with the hope that having a proven set of instructions will help civil trials run more efficiently, lead to fewer appeals over the instructions, and put less of a workload on courts.
In Maryland, the instructions were adopted by the Maryland Court of Appeals with assistance from legal scholars, other judges, and practicing attorneys. They are intended to be clear and impartial statements of both statutory and case law. Judges use pattern jury instructions when applicable to the case based on the facts and the law presented.
The reality backed up by a few studies is that jurors struggle to grasp the instructions that are supposed to guide their decisionmaking. These institutions are typically read very quickly in tone and language that is hard for the most sophisticated listen to comprehend. You would hate to see a quiz on the instructions given to a juror after hearing the instructions.
The answer is for trial lawyers to pull out the jury instructions that matter to them, blow them up, and explain them to the jury.
Every case is different. Issues of law and fact will be presented that will be different from the perfectly average case (a case we have never seen before). This is where non-pattern jury instructions come into play. They are based on the law just like the pattern instructions. These are just issues that do not arise often enough -- or there is some question about them - that they do not make it to the pattern instructions. We include some of the instruction we use the most frequently above.