By Michael Hartley
Dinosaur Dodger is an email game about probabilities. It takes a minute to start a game, then about two weeks for the game to roll on to the end. From time to time the game sends you emails telling you how well you are doing. Want to play? Read on...
It's your first day at your new job with the Lost Explorers Assistance Society. Your job is to advise lost explorers how to get home. You've just settled in at your new desk. The phone rings. You pick it up. A worried voice speaks.
- Explorer : Excuse me, is that the Lost Explorers Assistance Helpline?
- You : Yes. Are you a lost explorer?
- Explorer : Yes. I'm on the Bongo-Kazongo Track. I've reached a turn-off, and I need to know whether to go straight or turn.
- You : Just hold on a minute, sir, I'll check.
You call up a map of the Bongo-Kazongo Track. It's very dangerous. The track has two turn-offs, and the explorer absolutely must take the second turn-off. Otherwise, he'll get eaten by voracious dinosaurs!
You decide to ask the explorer some more questions...
- You : I need to know - are you at the first turn-off, or the second?
- Explorer : Well, you see... I can't remember.
- You : It's very important - have you already passed a turn-off, or are you still at the first turn-off?
- Explorer : Honestly, I can't recall. I've been bitten by a Latrodectus Amnesiaticus.
- You : A Latro-what??
- Explorer : Latrodectus Amnesiaticus. The memory-loss spider. I lose all sense of where I am and where I've been. I have an antidote at home, but I can't remember, for the life of me, whether I'm now at the first or the second turn-off.
- You : Just a minute, sir.
What will you advise the explorer? He doesn't know where he is! You ask your boss for advice.
- You : (after explaining the situation) ... so, what should I advise him?
- Boss : Roll a dice.
- You : What??
- Boss : This kind of thing happens all the time on the Bongo-Kazongo track. The whole place is infested with Latrodectus Amnesiaticus. So, just choose randomly whether to tell him "go straight" or "turn now".
- You : Oh. But what probability should I give to each choice?
- Boss : I'll leave that to you. I'm late for a meeting.
- You : But the explorer might get eaten by a dinosaur!
- Boss : It's their fault for going wandering off down the Bongo-Kazongo in the first place. Everyone knows it's riddled with dangerous amimals. Life's tough. Bye.
- You : But...!
- Boss : Ok, look, he might get eaten, true. He won't be the first. Just choose the probability you'll tell them to go straight, and stick with it. If you can save more than a quarter of these guys, then frankly, you're doing well. Now, I really have to go.
So you'll send the poor explorer at random either straight or right. Hmm... All right, but what probability will you give to each choice? What is the probability you will tell him to go straight? His fate depends on your decision...!
To play Dinosaur Dodger, fill out the form below. Every hour, the computer will assist an explorer on your behalf, based on the probability you choose. You'll get emails from time to time, until you've helped 200 explorers. Then, if you've done well, your name will appear in the high scores table!