None of the information here will matter if you don't have integrity. When people ask what integrity is, people say, "doing the right thing when no one else is looking." That's not wrong, but OCS, TBS, and the Marine Corps take integrity as a holy creed. A quick google search tells you that integrity is honesty, having a strong sense of morals. But what does this mean? Why is this important? And now does this apply to OCS?
If you are an "integrity violator", you will get dropped. No questions asked. Well, they may ask you questions, but in the end, you'll be dropped, and you'll be banned from ever attending OCS again.
Anything in this guide can be found in other OCS guides, or in knowledge your OSO gives you, or in official Marine Corps videos on YouTube. Therefore, there are no test answers or anything like that. I don't want anyone getting kicked out because of something I write. So be easy on me if there are things I can't go into.
Why is integrity important? Because one day you will have Marines under your charge who may actually die if you do not do the right thing, even if it is hard for you, and even if it is harmful to you or your career. You will be the officer, and if you do not do the right thing or take care of your Marines, then you shouldn't call yourself an officer.
When I was at OCS, during Week 7, I was given the Platoon Sergeant billet. I'll explain more about billets later, but the Platoon Sergeant billet is notoriously the hardest and most involved billet. I actually wanted this billet, because by this point, I had seen other people do it many times, and I wanted a chance to show my instructors that I wasn't a background character.
Anyway, my platoon had just finished the endurance course, so we were in the squad bay, cleaning weapons. Cleaning weapons in the squad bay meant your weren't PT-ing, and that you were inside. Two wonderful things in the winter. I had to walk up and down the squad bay, "inspecting" people's weapons, and since it was near the end of OCS, the instructors were off in the duty hut.
Being warm in the squad bay + little supervision + a little bit of responsibility = Time for shenanigans (in my stupid mind)
I told a some candidates, separately, that they were on "National Anthem Duty" the next morning. I told them they had to be the one to sing the National Anthem at formation tomorrow. When they got all nervous, I said JKKKKKKKK. Yep, I was that lame.
I get to one candidate, "Candidate Smith", and when I say JK, she starts laughing. Enter our Platoon Commander (a Captain).
"Candidate Smith! Do you think your performance here warrants you laughing?"
Enter our Platoon Sergeant, the one who was evaluating me, "Candidate Hart."
"Candidate Hart! This is your billet! Are you going to correct her or what??"
No lie, I was terrified. I paused awkwardly and stated,
"This candidate (me) is the reason that candidate (Smith) is laughing." I told my Platoon Sergeant it wouldn't happen again. My Platoon Sergeant gave me the look of death before disappearing into the duty hut. Some people in my platoon gave me dirty looks. I waited all day to be assigned a "chit", or an essay, or to be kicked out. But nothing happened.
Next week when my Platoon Sergeant was going over my evaluation, I was surprised I got "within standards." I used this as the time to apologize again. My Platoon Sergeant almost waved me away.
"Oh that? There's a time and a place for jokes, and that wasn't it. But you had the perfect opportunity to throw your fellow Marine under the bus but instead you stepped up and took RESPONSIBILITY for your actions. That took INTEGRITY."
Well shit. Fessing up wasn't me trying to show off my moral high ground, it was just natural for me. But I guess it made sense. It would make sense that a senior enlisted Marine's worst nightmare would be some boot officer blaming them for something that was the officer's fault.
People got dropped for lying. Even if the original infraction was minor, like hoarding a peanut butter packet. They were dropped for lying about it, not the actual hoarding. If you have an assignment that is late, just fess up, don't make excuses. If you ever feel like your instructors are questioning you about something, THEY KNOW. Just admit it.
But also, don't do shitty things. Someone in a male platoon got dropped for taking out people's wet laundry and putting his own in the working dryer. INSANE.
Don't blame people. If the whole platoon gets punished for something someone else did, just roll with it. Today them, tomorrow you. By the time I went to OCS, I had already gone to a Fire Academy, which was modeled off of boot camp. I was already aware of the mass punishments and boot camp shenanigans, and knew by this point it's better to just accept the suck, instead of blaming others.
I was not a good candidate. I struggled, and graduated 24th out of 28th in my platoon. But I honestly did not get yelled at often. For sure I got corrected many times for talking when I wasn't supposed to, or for laughing, but I was never pulled in front of the platoon and screamed at. The easiest way to get pulled in front of the platoon and screamed at is for complaining, blaming people, and being dishonest.
I hope you take this to heart, and just be an understanding and honest candidate. It helped me!