Several ways exist to protect against the copying of games but, when CD-ROM games were first introduced, were there any measures taken by video game developers to prevent the copying of games?

  • 12
    Not only was there little/no protections, the original Diablo game came with a second CD which you could use to install the game (multi-player only) on friends' machines.
    – David Rice
    Commented Nov 30, 2018 at 19:15
  • 5
    @DavidRice Except Diablo expects the CD to be in the drive at all times, so I guess they were effectively giving you 2 licenses. Happens I'm playing it right now... Commented Dec 1, 2018 at 1:58
  • 27
    Size. It required 500 floppies to make a copy of a full cd, so the media itself was the copy protection. Later all kinds of cd-copying protections were added. Commented Dec 1, 2018 at 11:57
  • 13
    Took a long time until CD-R devices become affordable enough to buy by most people. Commented Dec 1, 2018 at 21:58
  • 3
    Seeing a question about the first games on CD-ROM in retrocomputing comes with a bittersweet revelation about my age...
    – R. Schmitz
    Commented Dec 5, 2018 at 18:22

10 Answers 10


When CD-ROM games were first introduced, game developers didn’t take any measures to prevent users from copying them, for two main reasons:

  • CD-ROMs could contain more data than most hard drives at the time;
  • CD writers were rare, and extremely expensive.

The Wikipedia page on CD-R gives some idea of the expense involved: in 1990, CD recording systems cost over $35,000; by 1992, that had dropped to around $10,000, and the $1,000 barrier was crossed in 1995.

In those days, a hard drive large enough to store a copy of a CD-ROM (assuming the latter was filled to capacity) cost a significant amount too ($2,000 in 1992) — and you’d need one, on a SCSI system, to have any chance of copying a CD correctly. Blank CDs were also quite expensive.

Another limiting factor initially was that CD writers wrote CDs at the nominal speed, so copying a full CD would take over an hour (not counting the time it took to read it).

Many CD games did however rely on some CD characteristics to make them harder to copy to another medium: they’d check that their CD was present, or rely on audio CD tracks.

  • 21
    At the time I had my first CD writer around 1997, blank CD-R media was about £5 a piece. The occasional buffer underrun created very expensive drinks coasters.
    – bodgit
    Commented Nov 30, 2018 at 16:56
  • 2
    For games whose "meaningful" size is small, an easy way to protect a CD-ROM would have been to fill the CD with many copies of the game's data, each encrypted somewhat differently, and have the game select among them at random. Not only would the sheer bulk of the files have been an impediment to someone copying them all, but such redundancy could also allow the game to be usable even if part of the disk got damaged.
    – supercat
    Commented Nov 30, 2018 at 17:41
  • 23
    Yep, I remember my first CD writer in 1998 and it was the sort of thing where nobody had them and everyone ended up going to "that guy" who had one when they wanted things burned. It took 35 minutes to burn a disc and if anyone jumped in the room or your OS decided to take a crap instead of filling the write buffer you'd end up with a rather expensive coffee coaster.
    – J...
    Commented Nov 30, 2018 at 18:26
  • 3
    I would remove one reason listed and add one not listed. The reason that it could take a long time to copy a CD was not a deterrent to piracy. Before CDs and CD-Rs, we would take many hours and possibly a few days to copy floppy disk games from BBSes (local numbers only!) and then copy the floppies. It took a long time to copy a 7 - 10 disk games to another 7 - 10 disks. The reason I would add is that in the early days of CD-Rs, they were only single layer, which means they only held half as much data as a manufactured dual-layer CD-ROM. That made many disks uncopyable. Commented Dec 3, 2018 at 15:15
  • 6
    @ToddWilcox The important thing is that pretty much everyone could copy floppies - all you needed was two disk drives or a HDD. With CDs, it took quite a while for burners to become commonplace, so it was quite typical that one guy with a burner supplied hundreds of people with bootleg software, music and games. So floppy copying was highly parallelized - a friend came for a visit, you made a copy for yourself. CD burning wasn't for a few years; I've known a guy who had something like 16 burners just to keep up with the demand (back then we didn't even understand the concept of SW piracy :D).
    – Luaan
    Commented Dec 3, 2018 at 16:05

We had some software delivered on a CD in which the vendor purposely put a defect on a specific track. If that defect wasn't there, the software could say it wasn't an original CD.

Since defects are not copied, even on low level track copies, an exact replica could not be created.

  • 29
    Since defects are not copied, even on low level track copies, an exact replica could not be created. Though only until HDD capacity caught up. Then software drivers to emulate CD drives and create disc images, including the defects, started showing up.
    – jmbpiano
    Commented Dec 1, 2018 at 3:38
  • 9
    What first started copying the defects that @jmbpiano mentions, I wonder? I remember using Alcohol 120% or, was it DaemonTools?, in mid 2000s for that. Would that be on topic here?
    – muru
    Commented Dec 1, 2018 at 9:15
  • 10
    On a specific track? I assume you mean on a specific sector, because data on a CD is arranged in a single spiral track.
    – kasperd
    Commented Dec 1, 2018 at 9:19
  • 5
    I seem to remember the discs for the original Playstation had these defects, and one of the programs that could copy those defects was Nero Burning ROM. Commented Dec 2, 2018 at 11:00
  • 3
    I think it would be interesting to mention a date for that software delivered on a CD, because the question is about the first CD-ROM games. I would assume that intentional defects were introduced years later, when CD writers were much more common.
    – Didier L
    Commented Dec 3, 2018 at 23:11

(preface: While Stephen's answer already covers the basic points, I would like to put a different emphasis here - and merge in some private history :))

Short answer:

It was the game's size and the need to copy it to a CD again, combined with expensive and unreliable writers. Further, the CD itself was used as a copy protection. While games often got installed completely onto HD, they did check every now and then if the CD was still present in a drive connected, so people could not install and run it on multiple (friends') systems.

All of this is based around the fact, that copying CDs was expensive and unreliable - at least until the early 2000s.

In general, it's a bit like it was with floppies in the very beginning (my fist 10-pack did cost me 80 Marks), where copying to tape was prohibitive, just to be repeated in the mid 2000s when DVDs where rolled out when CD writing became cheap and reliable.

The Long Read

To start with, CD production was, at that time mostly confined to 'real' CDs and in a factory setup, as writeables not only where prohibitively expensive, but also did not always produce a result readable on (cheap) CD-ROM drives. When looking at prices it may be helpful to see that CDs weren't a thing for computer users until 1991's Soundblaster Pro got sold with a special interface for the Mitsumi CD Drive (and often packaged with one). Keep in mind this is about games. Here only mass market counts, not some high power users like many of us may have been.

CD as a game medium only started after that. At this time their sheer size was the most relevant copy protection. Game companies where often accused of adding unnecessary content to explicitly bloat the size of data used - including lots of clips and cut scenes together with purposely non-compressed data, to make it hard to copy games onto disks. In fact, numerous game reviews did test games that where delivered as a 'basic version' on floppies as well as their 'enhanced' CD counterpart and found that the CD-version didn't add anything useful.

While the cost for a CD writer in the mid-90s dropped close to 1000 USD, that's still above the usual juvenile threshold. And writers still suffered from compatibility issues with regular (cheap) players. Even if daddy did invest in the son's future by buying a PC with a well-fitted SCSI based machine including a writer, media prices were comparably high. When bought as a 25 pack, a single writeable CD was close to 10 USD. Thus copying did still bear high cost.

The time argument doesn't matter so much on the hobbyist side, as waiting an hour for the CD to complete (*1) could be filled with whatever teenagers do anyway :))

It doesn't matter on a 'professional' scale as well. Just remember all the copying that was going on during early 80s with pirated video tapes. People had a dozen VCRs in their garage, hooked up to a 'Master' and copied in real time. More or less the same way with CDs in the mid to late 90s. Machines did run multiple drives at once, just this time the master was a hard disk. 8-12 drives per machine and 2-3 machines did make it a full time job. Heck, they even developed robotic handling (*2). Again, the media price was more of a limiting factor (and readability) than time.

At a 'professional' level the danger for game companies was rather on the side of real CD manufacturing, as a standard CD manufacturing machine could be bought for less than some high-end PCs. The only costly part was acquiring the glass master.

*1 - Whoever could at that time cash out for a writer, would always also buy a simple reader that goes with it, so transfer can be done in a single run.

*2 - A good friend of mine was into this. He did the garage business for video tapes in the early 80s, and after some ... err ... troubles, slipped again into it with CDs. He had an awesome setup with two small robot arms handling the CDs of two drives connected to a single machine. That way he could have it run 24/7. He said it was good business, but I still think if he had invested the time it took to develop the software and handling mechanics in a start-up for robotics, he'd be a wealthy man by now. I just wish I had secured that machinery for my collection.

  • 1
    I don't recall the size of DVDs being much of a piracy deterrent. DVD writers came out less than a year after the DVD format was standardized, and hard drives large enough to hold one weren't unreasonably expensive. True, dual-layer recording took almost seven years to show up, but most software DVDs were single-layer, while video DVDs were transcoded to single-layer size (or more often, to 750MB or 800MB CD-ROM size).
    – Mark
    Commented Nov 30, 2018 at 21:06
  • 2
    @Mark DVDs didn't have the size issue because you could just burn the files to a handful of blank CDs. CD burners were cheap by then, and DVD burners didn't take long to get cheap. Big difference from when CDROMs first became popular and your options were either 450 floppy disks to cover one CD, or CD burners that cost over $1K.
    – mnem
    Commented Dec 1, 2018 at 15:58
  • Hah, and even with all those silly cutscenes, the hacker scene soon came up with compressed versions that could fit 10-20 games on one CD anyway. The only real "defence" the games had was subtle bugs that maybe cropped up in the bootleg versions, which only really served to make the feel buggy :D
    – Luaan
    Commented Dec 3, 2018 at 16:08

It's probably not exact but Sony back in the day had a really cool way of Protection against pirates:

Simply said they changed the CD itself... and made it "Wobble" in a certain way in the beginning so the reader knew it's an OEM Disk.

  • Sony got it from CD-R, a joint Philips and Sony spec, which uses this technique, called Absolute Time in Pregroove as a backwards compatible way of letting the drive know that a disc is writeable.
    – user71659
    Commented Dec 1, 2018 at 0:30
  • 6
    FWIW, the disc doesn't physically wobble. For the ATIP, the spiral "groove" has a slight wobble that the read head can pick up. On a related note, some people asserted that the "black" plastic used on PlayStation games was part of the protection, but if you hold them up to the light you can see it's actually dark red, transparent to the IR laser. (cf. cdrfaq.org/faq03.html#S3-4, cdrfaq.org/faq07.html#S7-24 )
    – fadden
    Commented Dec 2, 2018 at 16:52

In addition to Stephen Kitt's answer:

  1. Copy protection existed long before CDs; most of these techniques could be applied to CD-ROMs too. Many games that were shipped on floppies had copy protection - sometimes a question in the beginning that asked you to look at the booklet it came with, Monkey Island had a disk with 2 parts that you needed to set according to instructions to get the right answer.
  2. It was obviously much harder to distribute pirated copies then than it is now. The internet wasn't a thing so you were fairly limited in what you could acquire. Generally one of your friends had to actually buy the game. Sharing of games was fairly common, though.
  • 3
    Monkey Island had "Dial A Pirate"!! I forgot all about that. 3.bp.blogspot.com/_FbFu1YBZ-Hw/TT-zIIDZAXI/AAAAAAAAAlk/…
    – Jason Bray
    Commented Nov 30, 2018 at 17:59
  • Yep. was a great game all around.
    – xyious
    Commented Nov 30, 2018 at 18:02
  • 2
    while true, this would be more appropriately made a comment than an answer since it's not really relevant to the question. Commented Nov 30, 2018 at 18:36
  • Funnily enough, many games had their copy protection removed when they were re-published on CD! Commented Nov 30, 2018 at 18:40
  • As to point 2, many bbs's back then were full of pirated games/apps (though the long distance charges could add up to the cost of the games). I haven't played games since then but I had assumed it was much harder to pirate now. Don't most of these games require an active connection to some game server, this "game as a service" model?
    – Hasse1987
    Commented Nov 30, 2018 at 21:24

A quick review of the games consoles suggests that the Saturn and PlayStation were the first to implement copy protection as a firmware-level feature; between the 3DO, Mega CD and PC Engine there are some measures to ensure games are from licensed developers but no built-in protection against copies. I was also unable to find any evidence of software for those platforms implementing its own protection schemes.

So the answer seems to be: during the first wave of dedicated games hardware, no substantial effort was put into copy protection; one can guess that it just wasn't considered to be likely to be feasible within the usual commercial lifetime of a console prior to about 1994.

  • The most extreme example of this was the Dreamcast GD-ROM, which used a physically different format (two regions, one higher density, allowing up to 1TB per disc).
    – fadden
    Commented Dec 2, 2018 at 16:45
  • @fadden : Up to 1 GB per Gigabyte Disc Read-Only Memory" (technically called "GD-ROM"). Not one terabyte. Gigabyte.
    – TOOGAM
    Commented Dec 2, 2018 at 19:20
  • Although, ironically, isn't the Dreamcast the most recent console for which a hack was eventually found to run home-burnt games on an unmodified machine? Those that fit on a regular CD, at least.
    – Tommy
    Commented Dec 2, 2018 at 19:52
  • Yep, I remember burning a bunch of images to CD-R and they Just Worked in my Dreamcast, including the half-finished port of Half Life.
    – bodgit
    Commented Dec 3, 2018 at 12:21
  • @TOOGAM: whoops, yes, 1GB. 1TB would have been quite impressive. FWIW, there was such a thing as a GD-R, but you needed a custom drive to record them, and the blanks were hard to get unless you were a developer.
    – fadden
    Commented Dec 3, 2018 at 15:32

Besides the measures against copying the CD-ROM there were other things.

Pretty popular were dongles: specific hardware devices put one the parallel port. The game (or other software) did not run without those dongles. The dongles could not be copied easily.

  • 2
    Well... You say that, but some of them were just dumb "wire this pin to that pin" that could be replicated with a filed paperclip.
    – wizzwizz4
    Commented Dec 1, 2018 at 8:44
  • 3
    How many games had dongles? I never came across one... Commented Dec 1, 2018 at 15:25
  • 2
    @StephenKitt Dongles were more the purview of professional specialist software. Some still use dongles to this day!
    – 520
    Commented Dec 2, 2018 at 9:26
  • 4
    @520 I know what dongles are and where they are typically used ;-). I’m curious about specific mention of games in this answer. Commented Dec 2, 2018 at 9:28

From what I remember - most successful was the Serial Number approach when every CD copy had a unique hash to verify the unit copy. Verification process would request a hash to validate the copy and flag it useable. Serial number was included as a sticker inside the CD package.

  • How would that work? CDs (as opposed to recordable CDs) are mastered, so each copy is identical, to within manufacturing defect limits, and there is no real opportunity to introduce uniqueness to the process. Reading a whole CD on a contemporary system would take on the order of half an hour; nobody (to within experimental error) would buy a game that takes half an hour, or even 15 minutes (assuming you had one of those fancy quad-speed drives) to start.
    – user
    Commented Dec 2, 2018 at 13:03
  • Pressed CDs can't be serialized. In theory you can add a barcode in the disc hub, but most drives can't read it. You need to find a way to differentiate a pressed CD from a CD-R, which is possible, but doesn't involve a serial number.
    – fadden
    Commented Dec 2, 2018 at 16:57
  • The key for the software was included in the CD packaging as a sticker or printed on the paper. Verification was included in the software setup package, later online activation became more common.
    – charlie137
    Commented Dec 2, 2018 at 17:42
  • 3
    @charlie137 but before online activation, key verification wasn’t based on the specific CD being used; it used a variant of a checksum function. You could use any valid serial number with any CD (at least for games). Commented Dec 3, 2018 at 8:19
  • @StephenKitt I never said it was based on specific unit. Developer would include the validator in the game (easy example - Uplink), so you can have same image for the whole distribution batch.
    – charlie137
    Commented Dec 10, 2018 at 22:45

Afaict in the early days of CD-Roms, copying of the CD itself was less of a concern than running the game without the CD. It was only at the tail end of the 1990s that CD burners really went mainstream.

So when looking for their data files, (or in at least one case, a marker file full of garbage), games would look specifically for CD drives. If you copied the file to the same location on a hard drive, the game would just ignore it.


I am not 100% sure if the original question was just about the first CD-ROM games (so, I guess we're talking about the Late 1980's/Early 1990's?), but if the late 1990's are still acceptable, some games utilized an Illegal TOC as protection scheme.

The Table of Contents (TOC) is basically the description of the CD layout, that is, the position of individual tracks on the CD. Normally, you have 1 data track and then between 0 and 98 audio tracks, but some games pretended that there was a second data track (which didn't actually exist on the CD and might have pointed at the first data track) or other things that are just not "valid" according to the standards, but worked in consumer drives. Games could then check for the expected layout, which wasn't easy to duplicate at the time.

Some other games manipulated the file system (ISO 9660) to make it look like there was a HUGE file (multiple Gigabytes) on the CD. That file of course didn't really exist, but you couldn't copy it or create a file that large with regular tools on a copied CD, so Games would check for the presence of such a file of an expected size as a way to check for the original CD.

All these methods tried to achieve the same goal: Create a CD-ROM that was technically not valid according to the standards, but still worked properly. In many ways, this is similar to older Floppy-Disk protection schemes that also deliberately used bad sectors or illegal directory contents.

Most CD Burning tools at the time were made to create "proper" CD-ROMs with a valid TOC/File system structure, so they couldn't replicate these "deliberately defective" discs. This led to a bit of an arms race for a bit as better burning tools came along to try to duplicate these discs. I believe that a lot of the early CD Burners couldn't burn these kinds of invalid structures either, even if the software was otherwise capable of doing it.

However, it didn't take too long until a plethora of tools (I think CloneCD and CDRWIN were the original tools for duplication - along with new imaging formats like bin/cue and mds because the common .iso format couldn't duplicate the structure of the disc, just the data track) and most newly sold CD Burners could burn "invalid" structures without an issue. It's also when we learned about the difference between burning TAO (Track-at-Once) and DAO (Disc-at-Once), the latter being the required mode to create exact duplicates.

(Note: An Illegal TOC/File system is not to be confused with a regular oversize CD. Initially, CD-Rs had a capacity of 650 MiB. Some games were larger than that - for example, Anno 1602 was 684 MiB, and AFAIK you couldn't just omit stuff from the CD to get it to fit on a 650 MiB disc because the game checked. This type of protection scheme didn't last long because 700 MiB CD-Rs came along pretty quickly.)

  • 1
    TOC isn't basically a description of the file system. It basically a list of starting offsets for the tracks. The tracks can be audio or data, so there is no file system on an audio track which is more like a stream and data tracks contains blocks of data that can contain anything, including a file system.
    – Justme
    Commented Aug 11, 2023 at 18:23
  • @Justme Good point, I might be mixing in two different things: I remember some games used the actual TOC of the CD (that is, the data/audio tracks) to create invalid track layouts, and some other games used invalid ISO 9660 entries (to make huge files appear), but I don't remember all of the details since I don't have most of my CDs anymore to double check. I've edited to clarify. Commented Aug 11, 2023 at 18:26
  • 1
    TOC tricks being a hindrance for copying had more to do with poor software than anything else — DAO copying tools were available early on, and were necessary to properly copy audio CDs with gapless tracks before mixed-mode CDs with fake TOCs were a thing. In practice, such tricks weren’t ever much of a hindrance for games; pure audio CDs used similar techniques which did actually make them hard to copy, but were “OK” because they “only” needed to work in audio CD players. SecuROM and so on were a different matter altogether for games... Commented Aug 12, 2023 at 20:57

You must log in to answer this question.