"In our implementations, we use three kinds of objects. Walls, represented by dark grey blocks, cannot be occupied or walked through. Trainers' lines of sight are indicated by translucent rectangles. We have two types of Trainers. Weak Trainers, represented by red rectangles, are Trainers whom the player can defeat with certainty without expending any effort, i.e., without consuming PP or taking damage. Strong Trainers, represented by blue rectangles, are Trainers against whom the player will always lose.
"We can implement weak and strong Trainers as follows (a construction due to Istvan Chung). Weak Trainers each hold a Level 100 Electrode with maximum Speed and equipped with only the Self Destruct move. Strong Trainers each hold two Snorlaxes, with Speed of 30. The player has no items, and only one Pokemon in his team. For Generation I and II games (Red/Blue/Yellow and Gold/Silver/Crystal versions respectively), the player holds a Gastly which has learned Self Destruct using TM36, and its PP for its other moves have all been expended, so it can only use Self Destruct in battle. When the player encounters a weak Trainer, the enemy Electrode will move first and use Self Destruct, which deals no damage to Gastly because Self Destruct is a Normal type attack and Gastly is Ghost type, so the weak Trainer immediately loses. When the player encounters a strong Trainer, Gastly moves first and uses Self Destruct, causing the player to lose (even if it defeats the enemy Snorlax, the opponent holds another one). This implementation only works in Generations I and II because TM36 exists only in Generation I and the Time Capsule feature in Generation II allows a Gastly with Self Destruct to be traded from Generation I to Generation II. In Generations III, IV, and V, Gastly can be replaced by Duskull, which is allowed to learn the move Memento, which serves the same purpose as Self Destruct, via breeding."
https://arxiv.org/pdf/1203.1895.pdfFascinating stuff.
