First and foremost, let's define the term McDojo. Mcdojo is a term usually used disparagingly to refer to a martial arts school that is a "black belt factory," i.e., it awards Black Belts to many students who do not possess sufficient expertise to qualify as a Black Belt. When paying to learn a particular skill it makes sense to want to be able to use the skills that you've learned after paying for it. A McDojo gives you the feeling, or the accolades of one who has been through the training without actually having gone through it and unable to use the techniques taught to you. Below I have listed 5 red flags to be on the look out for when choosing a Martial Art/Self Defense School.
No Sparring! A school that never spars is a McDojo! You don't have to spar the first day you're there but sparring should be a part of the curriculum. If the school only does compliant drills, that's only akin to demonstrations, then the school is not equipping you with the ability to perform the movements against people that won't let you pull it off. The schools has no fighting, no tournament participation, no type of grappling application where someone is forced to tap even though they don't want to then it's not a Self Defense school or a Martial Art! No one will hold back when fighting you in the street and if that's your first time being punched it's a rude awakening, as Mike Tyson said "Everyone has a plan until they get hit." Martial Arts teaches you how to remain focused even while under duress of punches or being choked.
Incorrect Terminology This is a big red flag, martial arts is more than just fighting, it also carries the very culture of a people along with it. To misrepresent the culture is to cause disrespect to the culture. Kung Fu is from Chinese culture. A Kung Fu Instructor is normally referred to as a Sifu/Shifu. One of which is of the Cantonese language, the other Mandarin, which are both Chinese languages. An instructor of Chinese Martial Arts would never use the term on themselves as Sensei. Sensei is Japanese culture. Considering the horrific history of the Japanese occupation in China it would be disrespectful to Chinese culture to mix the terms.
Sensei is used for instructors of Japanese arts (Karate/JiuJitsu/Judo) Sabom is for instructors of Korean arts (Tang Soo Do/ Taekwondo/Hapkido). It's not set in stone that these people will call themselves this but they definitely wouldn't use another term from a different language to describe themselves. The word Qi/Chi is Chinese and not interchangeable with Ki which is Japanese. Look up the terms used in the school, if it doesn't track with the culture of Martial Arts being taught then it's most likely a McDojo.
"Too Deadly For The RING!" When using this term or something akin to it let's you know that the school is a McDojo. There are movements that aren't allowed in sport competition, not because all are too deadly. Unless it's some form of Gun Fu or Knife Jitsu it's not too deadly. There are moves that cause more harm than others, and out of respect for your opponent in a sport context you don't wish to cause them long term harm. The UFC has proven that you can practice your art, break bones, choke people out, and knock people out and both parties leave fairly safe. There are safe ways to practice your techniques under pressure, but saying an art is too deadly is normally a cop out so that the person doesn't have to show and prove that they know what they're doing. Are there differences between street and ring combat? Of course, but someone who participates in sport or at least spars regularly is more adept at using their techniques in the street than one who doesn't.
Testing Once A Month! If your school tests once a month it is unequivocally the base definition of what a McDojo is as described above. They're entire goal is to give you achievements without truly learning how to apply the techniques under pressure. Think of Martial Arts as a school. Public Schools or College have tests that comes after about 3 months of study time. These schools take up more of your time than a Martial Art School. If a Public School takes 3 months before giving you a serious test then why does a class that meets twice maybe 3 times a week for an hour test you earlier? Have you really learned how to be proficient at that current level within a month's time? Or are they trying to get you through the curriculum for marketing purposes and testing fees? Testing is a fundamental part of Martial Arts but no school should be forcing or pushing for any student to test before they're ready. Some students don't even like to test. Stay away from a "Black Belt" program because they're focus isn't on you knowing the material, it's only about making the school look good.
Can't Specify Their Style! If a Martial Art School uses general terms, such as Karate, Kung Fu, Taekwondo, or Jiujitsu but can't specify what exactly it is then that school is a McDojo. Karate has at least 7 subgroups, or sub category's that can be attributed to it (Shotokan, Gorin-Ryu Okinawan, etc.) Kung-Fu has over 20 different styles (Hung Kuen, Wing Chun, Tai Chi, Northern Shaolin etc). Even Taekwondo has specific categories they fit in to, ATA, ITF, WTF (World Taekwondo Federation but if they don't know that then WTF!). As mentioned earlier Martial Arts is more than just fighting, it carries with it the history and culture of the people that theart was born out of. They'd take pride in telling you what type of style it comes from, the history of the style, and it's uniqueness from other arts even within it's own category. If they can't answer that basic question, or at least have it somewhere mentioned on their website then it's more than likely a McDojo!
Be careful in choosing a school, know the questions to ask. Are there hidden fees? How often is testing? Are they forthcoming with testing fees? Is the price extremely high for the facility that they're working out of? Do they do tournaments are there forms because forms are a basic part of most martial arts and if there aren't why not? Does the answer make sense? Look it up online and is what they're saying in line with the culture of the Martial Art that they teach? If they're doing Kung Fu (Chinese Martial Arts) but can't speak ANY chinese it's definitely a red flag, same with Karate. If you speak more Japanese from watching dubbed Anime than they do then it's most likely a McDojo. Other than all of this, make sure you're having fun. If it's not fun for you it's not worth it, even if they're not a McDojo. Maybe that atmosphere isn't conducive to your own personal goals. Maybe it's a testing atmosphere, or a sport atmosphere, or a philosophical atmosphere with very little hands on training. Just know what your goals are and what you're getting in to.