The egg drop has many variations, but they all require you to protect a very fragile, uncooked egg from a high drop. This can be achieved with a very simple device, but it will require design and testing.
Step 1
Read and understand the rules for your egg drop contest. Find out what will be required of your design. How high is the drop? Must it survive repeated drops? Must it be waterproof? Will it be judged on how well it hits a target? Is there a weight or size limit? Are certain designs or materials not permitted? Does it need to made from things that are edible? Should it have a theme? Design to these requirements.
Step 2
Brainstorm ideas for your design. What do you think will help to protect an egg? What is happening when a falling egg breaks, and how can you prevent this? If it helps, draw pictures of your ideas as you go, or write down descriptions. Here are some suggestions to get you started, but try to think of ideas of your own, too.
- A hard shell. This might be a coffee can, a milk carton, or a shoe box. Think in terms of things you can easily obtain.
Padding. Cotton balls, tissue, bubble wrap, marshmallows, foam, fabric, and popcorn are all possibilities. 
A way to restrain the egg. It does no good if the egg keeps moving and breaks against the side of the container. Use the padding itself, or try tape, rubber bands, a sling made from old pantyhose, or your own idea. - A way to slow the falling egg. Some contests allow parachutes and similar mechanisms. Others do not. Remember that a parachute might decrease the accuracy with which your egg enclosure will hit a target, so read the rules before you choose a parachute design.
- Containment. Tape, string, glue, a buckle. Do you need to be able to open and close the container? You don't want your egg falling out.
Step 3
Evaluate possible designs. Which one do you think will do the best job? Choose the idea or combination you think will work best.
Step 4
Build your design. Will it work according to your plans? You can change your idea if building it turns out to be too difficult.
Step 5
Test your design. Don't wait until the contest to try out your design. You could learn a lot by breaking an egg or two in advance of the contest.
Step 6
Start by dropping the container empty or from a moderate height if you're not sure what will happen.
Step 7
Find a high place where you can safely drop your design. Try a high window, the bleachers at your school, or ask your parents to drop it from a a ladder. If you know how high the drop will be in the contest, try to drop yours from a similar height.
- If you can't get high up enough, get as high up as you can and throw the egg assembly in the air.
Step 8
Check whether the egg broke. If the egg did not break, congratulate yourself! Test a few times, just to be sure. If the egg broke, improve your design and test it again.
Tips
- The egg will break if it hits a surface. Try to design and build something that prevents the egg from hitting anything. (Suspending it inside a box using pantyhose works well)
- Test your design in the conditions of the contest, or as close as you can get to them.
- If your egg breaks, adjust the design based on what you think happened. Did the egg come out of the container? Did it hit the side? Did the padding transmit too much of the impact?
- Test the design you will take to the contest.
- Whether your egg breaks or not, try to learn from what happened.
- Have fun! It's not just any day you get to throw eggs off the roof of a building and call it homework.
- note: shaving cream works VERY well. Just fill a container halfway up with shaving cream, put the egg in, then fill the rest up. Make sure there are no major air bubbles or pockets
Warnings
- Egg may splatter everywhere if the container bursts open. One quality you may want to build into your design is the ability to clean it easily.
- Look below you before you drop anything and make sure there is nobody underneath.
- Take care not to fall when testing your design. Only the egg should fall.
