Luck manipulation (ConceptTopic, 4)
From Compile Worlds
Luck manipulation is something often done in TASes by abusing the psuedo-random number generators present in many video games. It can be done either by reverse engineering the game's RNG, recording the required input and then replaying with many different combinations of ignored input to affect the RNG, or simply by trying something over and over again until one gets what they want. The results can range from simply saving a few seconds (waiting for a moving platform, for instance) all the way to trivialising what would otherwise be a challenging battle system (like with the random effect spell in Madou Monogatari I). In rare cases, it can even be done without slowdown: in the GBA Fire Emblem games, the direction of an arrow would tell you whether the next number would be high or low, and after reloading from a savestate, you could use that information to tell which attacks would hit and miss.