I have never played The Oregon Trail before, but I'm wondering whether the path and events are pre-defined or random. For example, does doing the same action at the same point always result in the same result? Or are the results of every action randomized?

In other words, can you get through a play-through of The Oregon Trail by finding the most optimised path and doing those same actions every time, or can you always get screwed over by randomness?

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    Which game? There appear to be 22 editions, spanning from 1971 to 2021. en.wikipedia.org/wiki/The_Oregon_Trail_(series)#Editions. The most popular versions to my knowledge were the 1985 edition and the 1991 edition. Commented Apr 15, 2021 at 16:43
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    Do you care about how it's randomized? Like, if it's using Date / Time as a Seed, and can therefore be manipulated easily? Or do you just want to know if there is an element of randomness to it? ... Anyway, since you got an answer and can't invalidate it, you'd have to ask those as new questions.
    – Malady
    Commented Apr 15, 2021 at 19:48
  • @Malady The question was mostly 'can you run the same actions and finish the game every time'. So since every edition is random in some way, and there was no request of how is the random made in every edition, the checked answer is still valid and checked. Anyways, a question requesting how is the random in every edition of Oregon Trail would probably be considered 'Too Broad' like this one gaming.stackexchange.com/questions/351702/…, that was considered borderline.
    – Fredy31
    Commented Apr 16, 2021 at 19:46

4 Answers 4


The events in the game are random. Importantly:

In 1974, Rawitch was hired by the Minnesota Educational Computing Consortium (MECC), a state-funded organization that developed educational software for the classroom, and he began to rebuild the game, still using text-based output, for the organization. He decided to research the events of the Oregon Trail that he had not had time for with the original game, and changed the random events, such as bad weather or wagons breaking down, to be based on the actual historical probabilities for what happened to travelers on the trail at each location in the game. Rawitsch calculated the probabilities himself, basing them on historical diaries and narratives of people on the trail that he read.

Wikipedia - The Oregon Trail

Nothing in the information about the 1990 update suggests that the events were changed, merely the forms of various minigames, and an expansion of available backgrounds.

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    As an added trivia, you may want to add that specific versions and sequels of the game do indeed have hidden "paths" triggered by specific dates and locations. For example, taken from TV tropes: "In OTII, choose Salt Lake City as your destination and then choose to continue when you get there (as most people would) — which basically means trying to make it through the freaking enormous Great Salt Lake Desert, and then crossing the Sierra Nevada. If you chose the exact same year (1846) as the Donner Party, you indeed get the exact same late October snowstorm they got stranded in."
    – Ꮢedacted
    Commented Apr 15, 2021 at 10:17
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    This explains why I could never win the game. No matter how well fed or rested the people were, they would always die of something, or be washed out in a fording attempt (even in inches of water), or something else completely, well, random. Commented Apr 15, 2021 at 21:43

This is a supplement to the existing (correct) answers (with a potential caveat).

The source code may be found here for the 1978 version:


In it you can find multiple calls to RND, which confirms that the game does include randomness:

2600 IF 100*RND(1) < 13*B1 THEN 2710

However, from what I recall this is not a particularly robust randomizer, it may be possible to manipulate the RNG.

CAVEAT: Though from searching I have not found any speedruns where it was done, it wouldn't surprise me if there were ways to force a particular seed, at which point the game would actually run deterministically so long as the same choices were made at each point. You can verify this using an emulator / save states.

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    The RNG is not seeded at all in that source code. Generally speaking, that means that if the game is run immediately after a fresh boot, the same sequence of random numbers will be generated. This depends on the BASIC implementation but this source code is written in a highly portable subset of BASIC so it could be run on nearly any machine. (One way to "seed" an RNG is to generate and discard thousands of numbers over and over until the first time a user presses a key, but that is hard to do portably and isn't done here.)
    – Artelius
    Commented May 2, 2021 at 13:37

I found a way to contact Don Rawitsch and I sent him a link to this question, hoping he might answer it personally. Obviously he didn't, but he did send me a personal reply - I think he thought I had written the question!

Mark - Sorry I don't remember our meeting, but in answer to your question, the events in the original version of Oregon Trail were based on 1) fixed probabilities determined by information from pioneer diaries, and 2) those probabilities adjusted up or down a little at random each time the event occurred. In effect, the probabilities were a little different every time you played. -Don Rawitsch-

  • Hard to beat sourcing like this. :) Commented Apr 20, 2021 at 16:51

Yes and no.

Technically nothing in a computer currently is capable of being truly random, only pseudorandom, and certainly not back in 1971 when the game was first made and released. That said this is usually good enough for most uses particularly since 'gaming' randomizers isn't easy for humans, it is good enough for video games where the level of determinism in the pseudorandomness won't really be noticable.

If you're interested in randomness this is why Cloudflare has a wall of lava lamps in the lobby of their main office - they use the truer randomness of the physical movement in those to generate their random numbers.

  • Yeah the lava lamp thing is interesting! youtube.com/watch?v=1cUUfMeOijg But in games, usually randomness is done with something that is impossible to work with except with machine help (like number of cycles since the console/program was turned on.). So I would consider it as 'random' still.
    – Fredy31
    Commented Apr 16, 2021 at 19:49
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    @Fredy31 something like you describe would just be one of many inputs into a true random number generator. Usually you want to use as many sources of entropy as you can find. For most purposes a truly random number is necessary only for seeding your pseudo-random number generator. The pseudo-random number generators of today are much better than those from 1971. Commented Apr 16, 2021 at 21:32
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    @Fredy31 which is why the answer was yes and no, not just no - it's pseudorandom, but not truly random - but it would likely be possible to create a computer program to play two identical games of Oregon Trail it's not likely a human being would be able to, so it's "good enough"
    – Andrew
    Commented Apr 16, 2021 at 22:22
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    Agree to disagree. For me, if you could say do A then B to always get the same result C then that would not be random. If you could do frame perfect inputs to get the same result, but one frame off and the result is different, it is random. Even if we could say 'its not random as is' you would need to TAS to be able to abuse the not randomness. Saying its pseudo randomness is dancing around the issue.
    – Fredy31
    Commented Apr 17, 2021 at 12:57
  • The majority of modern computers have TPMs built in, which contain cryptographic entropy generators, so currently computers are capable of nondeterministic randomness. I also think this answer is probably confusing to those who don't understand pseudoRNGs and irrelevant to those that do. The key points are: (a) with the same seed, you get the same random numbers (b) @eps posted a version where this seems as easy as rebooting the machine! (c) when properly seeded, you essentially can't predict what will happen (cracking PRNGs takes heaps of data.)
    – Artelius
    Commented May 2, 2021 at 14:16

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