Deterministic Algorithms

In games, a deterministic algorithm is one that always produces the same result when given the same input in the same context. Just as moving by the same amount from the same position never changes the resulting position, game state can be reproduced identically by repeating the same sequence of inputs.

The key to implementing this is a fixed-frame game loop. Unlike the typical approach where processing time varies frame by frame, running game logic at a fixed time interval reduces variance caused by device performance and keeps results consistent.

However, since the cycle at which game logic runs can differ from the screen refresh cycle, prediction is applied to the display. By precomputing and displaying the next frame's movement and animation based on the last updated state, smooth screen rendering is possible even within a fixed-frame structure.

Probabilistic elements are handled deterministically using randomness that takes a seed. Using the same seed produces the same sequence of random numbers, allowing probabilistic behavior to be implemented in a reproducible way.

A deterministic design produces results that are less affected by differences in device performance, and serves as a foundation for implementing certain features.

• Keep the logic execution cycle consistent with a fixed-frame game loop
• Use prediction to compensate for the difference between the logic cycle and the screen refresh cycle
• Handle probabilistic elements reproducibly with seed-based randomness