We often hear that the IB Mock exams play different important roles, that can IMPACT your real IB score, and we're not talking about a situation where there is an ongoing worldwide pandemic that poses a major risk for students to go to school, hence the IBO has to use mock exams scores. We're talking when things are completely normal and you can do your real IB exams as well as the mock exams without any interruption.
So this is how the story usually goes: Let's say you miss your IB exams in May (the real exams) due to a valid and unavoidable circumstance (Example: you got really sick), you'll hear "the IBO will take your mock exam score, as your REAL exam score". Or Another story is that "the mocks will decide your predicted grades for University entrance, so you must have a good score".
"So are these true?"
To bluntly answer the question, Yes, these are real scenarios, and it does happen.
But it can be different for you. Because, each school decides how their mocks will impact their students, and they would also know how often universities approach them for mock scores. So it DOES matter, but not always, your school decides. And to know the specifics for sure, all you have to do is ask the coordinator of the exam in your school, because someone in-charge of this in your school will have the power to change your school's system for mocks independently.
So the next important aspect to understand before you make up your mind that mocks do matter is; Mocks are not ALL that matter. Do not assume that the predictive grades that are derived from your mock scores will be good enough in case you are not able to make it for the real IB exams. Plus here are some great advantages of the mock exams which you might want to consider since it can impact your at top universities and/or your real IB score (in case you miss the exams, or in case there happen to be a worldwide pandemic).
✅ The setting of the exam is usually the same as the real IB exam.
✅ You will be using past IB papers so you will feel the real challenges of the exam.
✅ Almost always you will be in the same examination room where you would have the real exam