Week 8 Tutorial: Break the game

Write the laziest, strangest and most cowardly simulated players you can, and find out whether any of them beats playing properly.

29 April 2027

Before the tutorial#

Think of the most annoying person you have ever played a game with. Bring their habits.

In the tutorial#

Corner camping. Circling the edge. Never picking up anything. Only ever moving left. Each one is five lines of code. Run all of them, 51 seeds each, against the intended strategy’s 101.6 s and 12 wins.

If something beats it, you have found a bug in the design and not in the code. Change one constant, run everything again, and check you have not made a different lazy player the new winner.

Where it goes wrong#

• A lazy player that is secretly another lazy player. The course’s first circling player scored a median of 17.4 s, the same as standing still, to the decimal. It started at the centre of the arena, where “which way is the edge” divides by zero, and never moved. Fixed, it scores 44.8 s. Two strategies that agree to the decimal are one strategy.
• Stopping at strategies that lose. Corner camping 18.6 s, moving only left 17.7 s, circling 44.8 s, running away 52.5 s: all far under the intended 101.6 s. That is a result, and a dull one. Keep going until one comes close, or say how many you tried.
• Fixing the winner and not rerunning the rest. A constant that beats one lazy player can crown another. Every row gets run again after every change.

What a finished answer looks like#

Intended: 101.6 s, 12 of 51. Run away: 52.5 s, 1 of 51. Circle the edge: 44.8 s, 0 of 51. Camp a corner: 18.6 s, 0 of 51. Nothing lazy comes within 49 s of playing properly, so I am changing no constant.

Afterwards#

The strategy table is this week’s quiz answer. Weeks 6 to 8 end here; weeks 9 and 10 are about what none of these tables can tell you.