Trade-Off Island

Trade-Off Island: production possibility curves and opportunity cost for Edexcel IGCSE Economics

This free game is part of our Pearson Edexcel IGCSE Economics (4EC1) course for exams in EXAM YEARS 2027-2030.

Run an island and watch the PPC come to life

Trade-Off Island is a free 3D game about the first diagram in Pearson Edexcel International GCSE Economics (4EC1): the production possibility curve (PPC), also called the production possibility frontier (PPF). It covers specification points 1.1.1 (b) to (d): opportunity cost, the use of diagrams to show a production possibility curve, and what the curve shows about the maximum productive potential of an economy, fully employed or unemployed resources, opportunity cost, possible and unobtainable production and positive or negative economic growth.

You run Brindle, an island that makes just two things: laptops and bicycles. It has five crews of workers, plus its land, factories and machines. Press MORE LAPTOPS or MORE BIKES and a crew walks from one factory to the other. Your orange point slides along a live graph of Brindle’s PPC, with laptops on the horizontal axis and bicycles on the vertical axis. Amara, Brindle’s chief economist, explains each idea as you meet it.

Plot the curve yourself

The game starts with every crew building bicycles: 60 thousand bicycles and no laptops, point A. You move the crews across one by one, and each move plots a point: B (10, 55), C (20, 45), D (30, 30), E (40, 10) and F (45, 0), the same table as the lesson. Each move also draws a step on the graph, with the laptops gained in green and the bicycles given up in red. Then the points are joined with a smooth curve that bows outwards. You can see why: each extra laptop costs more bicycles than the last, rising from 0.5 to 2 bicycles per laptop.

Ship the orders, reject the unobtainable

• On the curve: cargo ships arrive with orders such as 20 thousand laptops and 45 thousand bicycles. Find the point, move your crews and load the ship. Every point on the curve uses all of Brindle’s resources.
• Opportunity cost: every move shows what was given up. Moving from C to D gives 10 thousand more laptops for 15 thousand bicycles, so each extra laptop costs 1.5 bicycles.
• Outside the curve: some ships ask for a mix Brindle can’t make, such as 40 thousand laptops and 40 thousand bicycles. You learn to spot that it’s unobtainable and reject it.
• Inside the curve: when a crew’s machines break down, the crew sits idle on a bench and your point drops inside the curve. That’s unemployed resources. Put the crew back to work and you get more of one good with no fewer of the other, so there’s no opportunity cost.
• Shifts: a hurricane wrecks machines and roads and the whole PPC shifts inwards (negative economic growth). Then Brindle rebuilds with new technology and a training college, and the curve shifts outwards (positive economic growth). Orders that were unobtainable can now be made.

Learn it, then prove it

Every idea is taught in the game before you’re tested on it. Four quick checks ask exam-style questions: the opportunity cost of a move, the opportunity cost of one extra laptop, what a point inside the curve shows, and the opportunity cost of moving from inside the curve up to it. A wrong answer, or a wrong move such as loading the wrong mix or rejecting an order Brindle can make, brings up a short explanation with a “Why not?” and a link to the lesson. Then you try again. The end screen gives your rank and best score, and a one-page summary of everything you need for the exam.

The game takes about 7 to 9 minutes. It works with a mouse, a touch screen or the keyboard, needs no login and runs on school Chromebooks, so it’s easy to use as a starter or a plenary in an economics lesson.