Digital Physics refers to the immutable set of rules that define what is possible in a virtual world.
See Autonomous Worlds by Ludens and Composable Engineering by Guilty Guyoza
This is distinct from the prior existing notion of Games Physics which pertains to the simulation of entities movement and spatial relationship with each other. Digital Physics may refer to arbitrary rules like “an inventory holds a maximum of 4 items”, which would not be considered Game Physics.
Granularity
In practice, the design and implementation of digital physics exist on a spectrum.
Fine Grain | Course Grain | |
Abstraction | None | High |
Typically | Atomic building blocks with logic defining how they interact. | Arbitrary game rules. |
Real World Physics comparison | Closely modelled. | Not concerned. |
Example | Spatial geometry, with a closed system of energy transference that govern how entities move through space. | Maximum entries in an inventory. |
Advantages | Highly composable. | Engineered efficiently as a user facing system. |
Disadvantages | Over engineered for most user facing systems built on top. | Less composable. |
Examples
Downstream
Note that this table describes the current in-development state. They do not necessarily represent how the Digital Physics is designed- which is an on going process.
Language | Solidity |
Frame work | COG : Source
Game contracts define
◦ State schema.
◦ Rules for how state is modified.
Rules are immutable and the only things that can modify the game state so these define the Digital Physics. |
Example 1:
Move | Source
Granularity : Course
• Space is a hex grid.
• Only MobileUnits can move.
• MobileUnits have a single hex location.
• MobileUnits can change location from current hex to any other that exists (!)
|
Example 2:
Craft | Source
Granularity: Medium
• Base element is Goo.
• 3 kinds of Goo.
• Items are made of Goo or other items.
• New items can be registered with a recipe.
• Valid recipes have inputs that total at least double the goo required for output.
• Crafting can only be performed by a building that owns required inputs.
• Items can interact with core systems (e.g. combat) based on their goo constituents
• Items can interact with extensions (emergent systems) based on their unique ID and/or goo. |
Composability
The finer grained the digital physics, the more opportunity there is for composable engineering. The courser grained the digital physics, the easier it is to deliver satisfying user facing interactions (a lesson long learned by games).
Note that the composability of a world is not just a factor of the granularity of the digital physics. The API to the digital physics may encourage or deter building systems on top. For example, exposing logic hooks or providing an API that other worlds can compose with (see Natural Composability by Ronan).
However, fine grained, un-opinionated and highly abstract digital physics afford the most composable engineering opportunities.
A method for resolving the difficulty of building user facing systems with highly abstract ones is abstractcion (see the post AW assembly question, term coined by Non), where you build the user facing system first, then break it down into is component parts. This allows that system, and many others to be built.
Game scale or Global Scale
Digital Physics may be intended to be for a single closed game, a composable game world or many world sharing the same universal Physics. The intended use will likely drive the granularity with wider use require finer grained Digital Physics.