Creative Commons
On January 27th, 2023, Wizards of the Coast released the 5.1 SRD under the Creative Commons Attribution 4.0 International License (“CC-BY-4.0”). We provide that document here for convenience. The CC is a worldwide, royalty-free, non-sublicensable, non-exclusive, irrevocable license to reproduce and share the material in whole or in part. You should familiarize yourself with the license itself before using it.
The following text is from Wizards of the Coast
The System Reference Document 5.1 is provided to you free of charge under the terms of the Creative Commons Attribution 4.0 International License (“CC-BY-4.0”). You are free to use this content in any manner permitted by that license as long as you include the following attribution statement in your own work:
This work includes material taken from the System Reference Document 5.1 (“SRD 5.1”) by Wizards of the Coast LLC and available at https://dnd.wizards.com/resources/systems-reference-document. The SRD 5.1 is licensed under the Creative Commons Attribution 4.0 International License available at https://creativecommons.org/licenses/by/4.0/legalcode.
Please do not include any other attribution regarding Wizards other than that provided above. You may, however, include a statement on your work that it is “compatible with fifth edition” or “5E compatible.”
Section 5 of CC-BY-4.0 includes a Disclaimer of Warranties and Limitation of Liability that limits our liability to you.
Open Gaming License
Also on January 27th, 2023, WotC abandoned its plans to attempt to de-authorize the Open Game License v1.0a. As such, the 5E SRD is also available under that license. The OGL differs from Creative Commons in a number of ways, so make sure you are familiar with the license before using it.