GML

GML is an interpreted programming language used by Game Maker and stands for Game Maker Language. It is very flexible in its syntax (allowing '=' and '==' to be interchangeable in conditional statements for instance) and resembles curly-brace languages such as C.

Learning GML
For both non-programmers and programmers alike, here are some resources for learning GML

GML Equivalents for D&D Actions: This manual allows you to look up D&D commands and their corresponding GML equivalents.

GML For Non-Programmers This is the main overview of GML (found in the official docs) in an easy-to-read, freely-editable format.

GML Functions Overview This page contains an overview of all functions in GML.

Also see www.yoyogames.com/gamemaker/docs for the official complete documentation. You can also find the same documentation in Game Maker's Help file.

Asking Questions
Any questions you have while learning GML can usually be answered at the Game Maker Community (GMC). GMC requires membership to post, though, but membership is free and registration is easy.