The Higher School Certificate (HSC) is the culmination of 13 years of schooling for students in New South Wales, Australia. It is a qualification awarded to students who successfully complete their senior secondary education. However, the HSC is technically separate from the Australian Tertiary Admission Rank (ATAR). The ATAR is a rank used to determine university admissions and is calculated directly from a student’s performance in the HSC.
The HSC consists of a series of school-based “internal” assessments (school score) and final “external” government exams (exam mark). These assessments begin in the last term of Year 11 and continue through the first three terms of Year 12, with the HSC trials being the most significant internal examination for each subject (and designed to be a replica of the external HSC). The final (external) HSC exams are typically held in October of Year 12. The HSC is administered by the NSW Exam Standards Authority, or NESA for short, and the ATAR is calculated by the Universities Admissions Centre (UAC).
Whether you’re a student or parent in Year 6 or 7 trying to work it all out, or a seasoned senior-school veteran weighing up some tough dropping, scaling, and extension subject preferences, the HSC can be super daunting - so let’s break it down in the first part of this five-part series!
Note that this series is designed for beginners and explains everything from the ground up - look around, and you’ll find it’s the most comprehensive guide ever made and published on the entire HSC system! It can be a bit long, so if you’re already somewhat of an expert on this subject, you can skip to Article 5 for a brush-up on concepts, terms, and an overall HSC strategy that’s concise and useful.
Before students enter Year 11 and 12, they complete a broad curriculum covering compulsory subjects. Year 7 to 10 students engage with both compulsory subjects, such as English, Maths, unstreamed Science, HSIE, and PDHPE, and elective (choice-based) subjects, such as languages, arts, home economics, crafts, and more.
Students choose the subjects which they want to study in the greatest depth for their final 2 years (Year 11 and 12); these are the subjects that count towards their HSC and ATAR. Seniors start with three terms of “preliminary” content (from the first 3 terms of Year 11) and then move on to four terms of HSC content (as aforementioned, the last term of Year 11 and first 3 terms of Year 12). Only HSC modules (i.e., the last 4 terms’ content) is examined in the HSC. However, while preliminary content isn’t directly examined in the HSC, it forms the foundation for HSC topics, so it’s important to understand.
At the end of Year 10, students go through subject selection, where they choose the subjects they will study for Year 11 and Year 12. This is a crucial decision, as it determines what they will focus on for the next two years and can impact their ATAR, university options, and career pathways.
However, subject selection isn’t just about what students want to study—it’s influenced by several factors, including:
✅ Junior School Performance: Some schools have prerequisites for higher-level subjects (e.g., strong performance in Year 10 maths may be required to study Extension 1 Maths).
✅ Timetabling Constraints: Not all subject combinations are possible due to scheduling conflicts.
✅ Staffing & School Offerings: Some subjects may not be available at every school, depending on teacher availability and student demand.
✅ Future Goals: University prerequisites or career interests may influence subject choices (e.g., Chemistry for medicine, Legal Studies for law, etc.).
A student’s best subjects aren’t always the hardest or the ones that scale the most. Success in the HSC is about choosing subjects they enjoy, excel in, and can stay motivated to study for two years.
For more details on how scaling and subject selection impact ATAR outcomes, check out Article 3!
A student must study at least 10 “units” for the HSC. Think of “units” as “points” representing the amount of content in a subject. Most subjects are worth 2 units, but some extension subjects can add 1 or 2 extra units on top of a base subject, but the base subject must always be studied* (e.g., History Extension or Science Extension).
There’s no official maximum number of units a student can take, but schools typically cap it at 14-16 units due to timetabling constraints. While taking more units can provide a safety net (since only your best 10 units count towards your ATAR), overloading yourself with excessive subjects can be counterproductive—quality over quantity is key!
What this ultimately means is that most people will study more than 10 but less than 14 units for the HSC (but not necessarily in Year 12, as Article 4 might explain!).
Units only indicate the amount of content a subject covers, not its difficulty level. The rigor and competitiveness of a subject are accounted for separately in the scaling process (covered in Article 3).
For example, students studying 2 units of Chinese can choose from different levels, ordered in terms of difficulty:
Each of these subjects is worth 2 units, meaning they require the same volume of study (i.e., there are the same number of topics and outcomes in each subject). However, the difficulty varies significantly, and this is reflected in the scaling process. A student scoring 85% in Chinese Continuers may receive a higher scaled mark than someone scoring 85% in Chinese Beginners, because Continuers is considered more challenging overall and an 85% is worth more to an ATAR, which is a ranking.
This applies across different subjects—choosing a higher-level subject might boost your ATAR if you perform well, but it’s important to pick subjects that align with your strengths and interests rather than just chasing scaling benefits. Scaling is covered more in Article 3.
The HSC offers a wide range of subjects across different disciplines, allowing students to tailor their studies to their strengths, interests, and future goals. For simplicity, this guide will only analyse NESA Board-Developed Courses (excluding VET and other courses which do not count for an ATAR).
English is the only mandatory HSC subject, and students must study at least 2 units at one of the following levels:
📖 English Studies (basic, limited ATAR eligibility)
📖 English Standard (general level)
📖 English Advanced (more analytical and essay-focused)
📖 English EAL/D (for students with English as an additional language/dialect)
📖 English Extension 1 (for high-achieving Advanced students)
📖 English Extension 2 (for students studying Advanced and Extension 1 and who wish to also compose their own major text in Year 12) (Year 12 only)
These subjects have a single 2-unit version and do not have multiple levels or extension options. Examples include:
⚖️ Legal Studies
💰 Economics
📜 Business Studies
🗿 Society & Culture
🎭 Drama
🖼 Visual Arts
Some subjects offer different levels of difficulty, but all levels are still worth 2 units:
➗ Mathematics (Standard, Advanced)
🌎 Languages (Beginner, Continuers, In-Context, Literature)
Subjects with Multiple Syllabuses
Some subjects have two curriculums that are similar in difficulty but cover different topics to cater for student preference. Examples include:
Music 1 vs Music 2 - both require the same practical and theoretical skill, but Music 1 focuses on popular music, while Music 2 focuses on Western traditional music and allows for extension.
Mathematics Standard 1 - a non-ATAR course that covers basic math concepts, while Mathematics Standard 2 is an ATAR course covering more advanced math concepts.
Certain 2-unit subjects (in addition to English) allow students to take an additional 1-unit extension course, usually in Year 12 only (the subject is not studied in Year 11, except for English and Maths extension). The extension course is much more challenging than the base subject, and it often involves studying unique elements of a course (often near university level) and completing different forms of assessments to corresponding 2-unit subjects. Taking on one or more extension subjects means that the number of units a student takes in Year 12 will increase if a subject is not dropped (see below!)
🔬 Sciences: biology, Chemistry, or Physics (2U) → Science Extension (1U)
📜 History: modern History or Ancient History (2U) → History Extension (1U)
🎭 Languages: Japanese, French, Chinese, etc. Continuers (2U) → Language Extension (1U)
Mathematics is an exception. Students studying Maths Advanced and Extension 1 for Year 11 can take the following sequence in Year 12:
🧮 Mathematics Advanced (2U) → Mathematics Extension 1 (2U) → Mathematics Extension 2 (2U)
This is the only subject where a 1-unit extension counts as 2 units (but only in Year 12), and it means students in this pathway only study Maths Extension 1 and 2, skipping the regular Advanced syllabus.
It’s also important to note that subjects worth a different number of units are scored differently.
We’ll see how we get these scores, and also how they’re actually put together to make an ATAR, in Article 3.
The flexibility of the HSC subject system means students can pick subjects that match their strengths. There aren’t any prerequisites set by NESA, but some students focus on humanities, others on STEM, and some aim for a balanced mix. There are also options to do certain HSC subjects at different times, paces, or levels, but the key is understanding how scaling works (covered in Article 3) and choosing subjects that align with your abilities and goals!
Those of you who are more perceptive may also have noticed that if many extension subjects picked in Year 12 only increase the number of units, then there must be a corresponding way to decrease units - dropping - to maintain a good timetable and your sanity!
Just as a student can take on subjects (e.g., by choosing 2 units of Maths Standard for Year 11 and 12), change out a subject to increase its difficulty for the same number of units (e.g., by picking up 2 units of Maths Advanced instead of Maths Standard), and take additional extension courses that count for more units and much more study (e.g., choosing Maths Extension 1 on top of Maths Advanced, and hence studying 3 units of maths), a student can reverse all these processes by dropping subjects, levels, or extensions at any time during Year 11 and 12.
The only hard rule of dropping is that your total units studied cannot drop below 10 at any time (and some schools stipulate a minimum of 12 in Year 11). You can theoretically drop any course from the first day of Year 11 right up until you enter the exam hall for final examinations, but obviously there are strategic decisions to be made when choosing to drop any subject. We’ll cover this later on in our subject selection and dropping guide in Article 4!
Sure! Let’s meet five model students who all attend the same school, who we’ll follow throughout the series as we look at their subject choices, schools, scaling, accelerating, dropping, uni choices, and final ATARs! More detailed examples will be covered in Article 5, including profiles of students. For now, we’re only looking at subject choices and how they add up to more than 10 or 12 units.
Jasper is your classic selective school top performer. He thrives on academic challenges and is always aiming for perfection in his studies. With a dream of getting into medicine at UNSW, Jasper is laser-focused on maximising his ATAR.
He’s passionate about all subjects but has a particular love for science and mathematics, making Chemistry, Physics, and Extension 2 Maths his top priorities. He also takes English Advanced and English Extension 1 to ensure he’s well-rounded. Jasper spends hours perfecting his notes, using high-level study resources, and practicing past papers religiously. While he sometimes puts too much pressure on himself, he balances his workload with debating and volunteering at a local hospital to strengthen his medical school application. He also studies Biology to set him up nicely for medicine, because his school allows for 3 science subjects (covered in Article 4).
| Subject | Units | Prerequisite 2-Unit Subject? |
|---|---|---|
| English Advanced | 2 | N/A |
| English Extension 1 | 1 | English Advanced |
| Mathematics Extension 2 | 2 | Mathematics Extension 1 |
| Mathematics Extension 1 | 2 | Mathematics Advanced (Year 11) |
| Chemistry | 2 | N/A |
| Physics | 2 | N/A |
| Biology | 2 | N/A |
| Total Units | 13 | — |
Rachel has always had a knack for numbers. From an early age, she loved solving problems and uncovering patterns, which naturally led her to maths-heavy subjects in the HSC. She dreams of studying Data Science and Artificial Intelligence, possibly at USYD or UNSW.
Her HSC subject choices reflect her STEM-oriented mindset—she’s excelling in Mathematics Extension 2, Software Design & Development, and Physics. She enjoys coding and spends her free time competing in hackathons or working on personal programming projects. English and Business Studies aren’t her favorite, but she understands the importance of strong communication and finance skills in the tech world.
| Subject | Units | Prerequisite 2-Unit Subject? |
|---|---|---|
| English Standard | 2 | N/A |
| Mathematics Extension 2 | 2 | Mathematics Extension 1 |
| Mathematics Extension 1 | 2 | Mathematics Advanced |
| Software Design & Dev | 2 | N/A |
| Physics | 2 | N/A |
| Business Studies | 2 | N/A |
| Total Units | 12 | — |
Scott is the kind of student who could debate for hours about historical events, political theories, or ethical dilemmas. He’s fascinated by how the world works—politics, law, economics, and philosophy—and he’s hoping to turn that passion into a career in law or journalism.
His HSC subjects are heavy on essays and analysis, with a mix of Modern History, Legal Studies, and Business Studies. He’s also taking English Advanced and History Extension, where he can dive deep into historical interpretations. While he struggles with maths, he makes up for it with his ability to write sophisticated essays and form strong arguments.
In his free time, he’s either reading political theory, writing articles for the school newspaper, or competing in Model UN.
| Subject | Units | Prerequisite 2-Unit Subject? |
|---|---|---|
| English Advanced | 2 | N/A |
| Modern History | 2 | N/A |
| History Extension | 1 | Modern and/or Ancient History |
| Legal Studies | 2 | N/A |
| Business Studies | 2 | N/A |
| Mathematics Standard 2 | 2 | N/A |
| Total Units | 11 | — |
Amelia is the life of the party. She’s always up for a chat, loves being around people, and is involved in every extracurricular under the sun—from school musicals to social events. While academics aren’t her main focus, she’s determined to graduate and find a career that suits her outgoing personality.
She’s interested in marketing, event management, or media and has picked subjects that allow her to be creative and engaged. Business Studies, Drama, and Visual Arts give her a mix of analytical and creative skills, while English Standard and PDHPE help her keep up her marks.
Amelia often struggles with procrastination but shines in group projects and presentations. She’s considering a career in PR, event planning, or hospitality management.
| Subject | Units | Prerequisite 2-Unit Subject? |
|---|---|---|
| English Standard | 2 | N/A |
| Business Studies | 2 | N/A |
| Visual Arts | 2 | N/A |
| Drama | 2 | N/A |
| PDHPE | 2 | N/A |
| Total Units | 10 | — |
Mohammed moved to Australia in Year 4 and grew up speaking Arabic at home. He’s bilingual and takes pride in his heritage. His family runs a small business, and he’s eager to help out while also planning to study business or finance to take the company to the next level.
Mohammed excels in practical subjects and enjoys working with numbers. He’s taking Business Studies and Mathematics Advanced, to develop his entrepreneurial skills. Since English is his second language, he’s studying English EAL/D, which helps him refine his writing and communication. Since he speaks Arabic at home, he’ll take Arabic continuers so he can make the most of his existing language skills.
In his spare time, he’s always helping out at the shop, learning about investments and finance, or planning his own future business ideas.
| Subject | Units | Prerequisite 2-Unit Subject? |
|---|---|---|
| English EAL/D | 2 | N/A |
| Mathematics Advanced | 2 | N/A |
| Business Studies | 2 | N/A |
| Arabic Continuers | 2 | N/A |
| Retail Services VET | 2 | N/A |
| Total Units | 10 | — |
These tables make it easy to see each student’s subject load, unit count, and whether any extensions rely on a prerequisite 2-unit subject. The main takeaways are that each student studies at least 12 units for Year 11, 10 units for Year 12, extension subjects require the highest-level corresponding 2-unit subject, and there are many difficulties of subjects and combinations that suit everyone (but also make for a complex system!)
We’ll cover how subjects change from Year 11 to Year 12 (and other years too!) in future articles, so read on to learn about how the ATAR is calculated!