About the Contest
The American Computer Science League (ACSL) is an international computer science competition with a history of over 40 years, offering divisions from elementary through senior high school (Senior / Intermediate / Junior / Classroom / Elementary) and testing computer science theory, data structures and programming across four rounds from December to May.
Each round combines a written theory test with a programming problem: the theory section covers number systems, Boolean algebra, data structures, graph theory and more (no calculators allowed), while the programming section supports nearly 20 languages including C++, Java, Python, JavaScript, Go, Kotlin and Rust.
Students with the best cumulative scores across the four rounds are invited to the All-Star Contest finals, competing against top performers worldwide. ACSL's progressive format is especially well suited to students starting from zero and aiming to build computational thinking systematically.
Key Facts
- Over 40 years of history with five divisions from elementary to senior high school
- Dual assessment of written theory (no calculators) and programming
- Nearly 20 supported languages including Python / Java / C++
- Four cumulative rounds leading to the All-Star finals
Participation Info
- Suitable Grades
- Grade 3-12 across multiple age divisions
- Contest Time
- Four rounds from December to May
- Format
- Written theory test plus programming problems, online
LighTon Coaching Programmes
ACSL Training Courses
Foundation Course
For students new to the contest
- Systematic coverage of the syllabus and key terminology
- Build a solid framework bridging schoolwork and contest level
- Small group or 1-on-1, online and in person
Intensive Course
For students with a foundation aiming at awards
- Past-paper drills with proven question patterns
- Topic training with biweekly tests to adjust priorities
- Progress reports keeping parents in the loop
Sprint Course
For students nearing the exam date
- Full mock exams with question-by-question review
- Targeted gap filling and score-maximising strategy
- Exam mindset and time-management coaching
Tutors
ACSL courses are taught by subject-specialist tutors with years of international curriculum and competition experience.
Meet LighTon's Select TutorsTrack Record
- Our students regularly win awards in major contests — results updated continuously
- Students consistently achieve top grades in the matching IB / AP / A-Level subjects
Frequently Asked Questions
Which grades is ACSL suitable for?
Grade 3-12 across multiple age divisions
When is the ACSL held?
Four rounds from December to May
What is the format of the ACSL?
Written theory test plus programming problems, online
What ACSL coaching does LighTon offer?
LighTon offers foundation, intensive and sprint courses for the ACSL, in 1-on-1 or small-group formats, online and in person. Contact us for a free preparation plan and a trial lesson.
Preparing for ACSL?
Book a free consultation for a personalised preparation plan and coaching schedule.