( permalink: funplosion.com/free )

This article has two goals:  

1) To give you some basic information to help you in digging deeper and verifying that the "free" stuff you're using in your game probably won't get you sued into oblivion.

2) To provide you with some links to quality free content (graphics and audio) to use for prototyping or releasing games, particularly for XNA developers on the Xbox.

  I am not an expert, and can offer no guarantees, but hopefully you will find the information and links useful.

(Please note: I am not a lawyer, and this is not legal advice.  I'm a fellow developer that has tried to research these issues, but copyright and licensing are thorny subjects and the consequences for getting it wrong in your game can be very steep. Consider this article just a starting point and verify things for yourself before you use any given content in your game.)

A common topic of inquiry among new indie game developers, myself included, is "Where can I get free assets (artwork / sounds / 3D models) for my game?"  A couple minutes with google will likely turn up numerous pages and long lists of websites proclaiming free graphics and sound effects, but the reality is rather more hazy than that.  Have these images really been made "free" by the artist, or is it more like "fell off the back of the truck" free.  Many sites offering free graphics are simply images scraped from commercial games by fans.  If you use them in a game, especially a commercial game, you are tempting fate and opening yourself up to a possible legal and financial nightmare.  Even among the sites which legitimately offer assets for "free", you have to look carefully into the licensing because much of the free content out there is free only as long as it's not used commercially.  If you're making an indie game to release for sale on Xbox Live, obviously that becomes a problem.  Other words to be leery of include Public Domain and Creative Commons.

Why so skeptical about "Public Domain"?  

Many unscrupulous (or merely lazy) sites use public domain simply as a short-hand for "it's on the internet so I'm assuming it's free".  Assumptions are always risky, even moreso when you're pursuing a commercial endeavor like creating an Xbox Live indie game.  A random website's lackadaisical concern for licensing is not going to protect you from having your game unceremoniously yanked from the marketplace, or protect you from lawsuits.    

Why so skeptical about Creative Commons?

Don't misunderstand, Creative Commons is awesome.  The issue is that "Creative Commons" is an umbrella term that represents a broad spectrum of possible licenses that put varying degrees of constraints on how the author's content can be used.  Some Creative Commons licenses only allow you to use the work in full, with no modifications.  Others allow you to use it only if you make substantial changes.  Most require attribution (giving credit to the content creator) and some allow use only for non-commerical purposes.  If a site just claims "these are free under creative commons" without specifiying which Creative Commons license, personally I would view that as a big red flag.

What about Fair Use?   

Often the term is just another form of lazy hand-waving, a catch-all term people trot out when they want to use something for free.  Fair Use is complicated, but I have a post that goes into a little more detail on Fair Use and Video Games - the linked article covers a couple common misconceptions about Fair Use and sources for further info.

So, the take home lesson is...

When on the prowl for free assets, be skeptical!  Do your due diligence, and if things look fishy just move on.  As boring as this process may be, keep in mind that you are looking to release a game to Xbox Live.  People are going to (hopefully) be giving you real money in exchange for your awesome game.  This isn't just for funsies anymore, and you should pay the same attention to detail to content licensing as you would to any other aspect of your game.    

Here are the sorts of questions you should be looking to answer when you come across "free" content:  

- Does the person claiming the assets are free really have the authorship or legal rights to do so?  

- Do they sound like they know what they're talking about or like they're just lazy and could care less whether something is honestly, legally, free?

- What license are these released under?  Does the license allow for commercial use? What other constraints has the author put on the use of the content? (e.g. does it require Attribution?)    

- If in doubt, consider emailing the content creator (occasionally they can even give you permission to use their stuff under a different license)

NOTE: I've found that in general, when a site is legitimately offering something for free, they are either A) the creator of the content, or B) they are hosting content from multiple people and have a proper legal/licensing/FAQ page which helps explain how the content may be used.  If you are finding neither of those things, then I would be very leery of using that content in your game.    

In summary, at this point it should be clear why as an XNA Game Studio developer "Where can I get free assets?" is the wrong question to ask.  What you really need to ask is "Where can I find assets that are free of charge, royalty free, and ok to use in commercial games?" inevitably followed up by "Are there any other constraints the author has placed on the use of this content (such as requiring attribution) which I need to be aware of?".      

On to the free stuff:

I've done a fair bit of searching and sifting looking for quality assets for my own use, trying to track down those elusive sites that offer content that is truly "free" for use to XNA developers making a commercial indie game for Xbox Live.  In the hopes that others will also find them useful, below are links to some sites that, to the best of my knowledge, provide legitimate "free of charge",  "royalty free" and "OK for commercial use" content.  

(Be aware that not all of the content may be free and even among the free stuff at a given site they may be offered under different licenses. Licenses can change. Also I am human and can make mistakes.  As I mentioned in opening this article, it is best to just think of this page and these links as simply a starting point for your own search, and verify things for yourself before you use any given content in your game.)

Free Game Graphics (mostly 2D)

Danc's LostGarden.com

There are several high quality sets of graphics here, including free sprites and textures

Graphics License

FlyingYogi's SpriteLibGPL

Several complete sprite sets here, suitable for almost a dozen different types of game: tank combat, shooters, asteroids, etc 

Graphics License (same page, towards the bottom)

Reiner's Tilesets 

Numerous 2D sprites with multiple frames for animation, as well as some 3D graphics and even sound fx

Graphics License

XNADevelopment.com Sprites 

Variety of clean, simple, sprites and some background images

Graphics License (same page, OK for commercial games)

GamePoetry.com Sprites and Tilesheets 

A handful of slick medieval RPG'ish sprites and tilesets

Graphics License Clarification (same page, in the comments)

Mayang.com textures 

Lots and lots and lots of textures

Graphics License (same page, towards the bottom)

CGtextures.com

Tons of categories and a generous commercial-friendly license

Graphics License

Free Game Audio (Music and Sound Effects)

Incompetech.com    

A great selection of free music from an audio professional.  A broad variety browsable by collection, genre or feel.

 Audio   License

Soundjay.com   

This site has several categories of sound effects and a handful of music tracks.  The quality is good although the audio is not necessarily game-focused.

Audio   License

Nick Gravelyn's techno music   

Some hobbyist techno from one of the XNA VIPs.

Audio   License (on same page)

Tread carefully.  There is some useful stuff here, but not all of it free and not all of it with confirmed licensing info.  Their FAQ explains more, but basically there are three distinct kinds of music and sound fx on their site:

1) Some "free royalty free" music and sound effects which they created and are making available for free

2) Some "royalty free" audio which they created and are selling

3) Some audio labelled as "public domain" or "personal use" which they did not create, and are offering for download but disclaim any responsibility for it's use and/or legality.  I would strongly recommend you stay away from this last category for your game.

Audio   License

ccMixter.org   

A huge site, with tons of music, mashups, and mixes created by a very active community of musicians who constantly riff off each other's stuff.

Note that the license varies from song to song and not all allow commercial use, so make sure you check.  Another point to be aware of is that much of the music from this site is licensed under the Creative Commons Sampling+ license, which is one of the more confusing ones. CC Sampling+, depending on how you interpret it and who you ask, seems to require that you not use the content as-is and uses vague terms like "highly transformative" and "insubstantial portion".  How transformative is enough?  How much can it be used until it's no longer insubstantial?  Don't ask me... not a lawyer.  Nonetheless, a good site to be aware of.  If in doubt, as always, don't be afraid to contact the content creator.

 Audio   License (varies by song, but generally flavors of the main CC licenses or the CC Sampling licenses)

FreeSound.org  

FreeSound is everything ccMixter is, but for Sound Effects rather than Music.  Note that all of the same caveats apply, only moreso.  Not everything is OK for commercial use.  CC Sampling+ is the default license used here for everything, but that may change at some point in the future with "freesound 2.0".

 Audio   License 

If you are aware of any other quality "free" content that you rely on, or found this article useful, I'd love to hear about it!  Feel free to leave a comment or reach me via the Contact page.  Also if anyone notices something I have misstated or feels is unclear feel free to drop me a line and I will do my best to correct it.