OpenTTD

Everything About Fiction You Never Wanted to Know.

In 1994, Transport Tycoon was released by Microprose after being developed by Chris Sawyer. In 1995, an upgraded version was released called Transport Tycoon Deluxe. This is not that game.

In 1996, Josef Drexler released the first version of TTDPatch, a program designed to patch Transport Tycoon Deluxe when you launched the game, to allow heavy changes to the game without breaking copyright laws.

By the middle of the Turn of the Millennium, TTDPatch was really starting to show its age. Despite amazing improvements to the game, the loophole which made the process legal restricted what could and couldn't be done, so work was started by the community on TT-Forums on a game called "Transport Empire" that was intended to replace TTDPatch to some degree. This is not that either.

OpenTTD is a business management simulation game based very heavily on Transport Tycoon Deluxe.

A screenshot of unmodded OpenTTD.
A screenshot of unmodded OpenTTD.

It was programmed in C by Ludvig Strigeus starting in 2003, and released the first version in March of 2004 to much surprise (you had to be deep into the community to notice it was being developed, due to the aforementioned "Transport Empire" being years away from completion but considered to be the most likely way to successfully move forward from TTDPatch at the time), eventually undergoing a conversion to C++ from 2007 onwards. After 20+ years of development, OpenTTD is still going strong, however the "bleeding edge" is the JGRPP fork (Jonathan G. Rennison's Patch Pack) that has been outpacing the primary branch in new features since it was first released in mid-August of 2015.

As in the official games by Chris Sawyer, the apparent object of the games is to end up with a monopoly of transport services for a usually randomly generated map. Transport is provided in all major modes; air, rail, road, and water, though the most profit tends to come from rail and then air. This is often thrown out the window in favor of making extremely efficient rail super-networks, or just building a train set out of the map for your own enjoyment. Oh, and there's multiplayer too.

OpenTTD was established around the same time as the less-remembered official pseudo-sequel Locomotion, and unlike the latter, is still going strong (tropes exclusive to OpenTTD and the JGR Patch Pack version of it are both listed on this page).

Compare and contrast N.I.M.B.Y. Rails, Simutrans, Mashinky, Voxel Tycoon, Railroad Tycoon, Industry Giant, Sweet Transit, Railgrade, Cities in Motion, Soviet Republic, Transport General, Chris Sawyer's Locomotion, and the Train Fever games, all of which focus solely or significantly on vehicular logistics.

Also compare and contrast A Train, Sim City, Cities Skylines, Theme Park and Theme Hospital, Software Inc., Roller Coaster Tycoon, Parkitect, and Power to the People, games with similar interfaces but a different industry or purpose to focus on.

Contrast Factorio and Satisfactory, which both have comparably complex rail, air, seaport and road infrastructure but also a scope well beyond logistical entrepreneurship.

Not to be confused with OpenGFX/OpenSFX/OpenMSX (which are the base graphic/sound effect/music sets available, see below), ChatGPT, OpenXR or OpenSea.

OpenTTD uses a lot of "tricks" to make modding relatively easy for the end user, but these have a drawback in that there is an overly complex ecosystem of game mods instead of simply files to download and use...

  • "NewGRFs" are what people typically think when they hear "game mod". You can program most new content using NML (NewGRF Meta Language, a custom programming language based on XML). These can be downloaded from the game's built-in downloader (which connects to a community-run content server and downloads content in compressed .tar files) or downloaded as files with the .grf format.
    • Unlike many communities, the OpenTTD community takes piracy of NewGRFs very seriously. The irony of this being the case for an "open source" game made by reverse-engineering a copyrighted work is not always lost, but two bad apples and a few other community incidents have led to strict enforcement of licensing of graphics (even though the code cannot be copyrighted as OpenTTD has a GPL v2 license on its own code).
  • "Base Sets" are like NewGRFs, but serve as the basic landscape tiles and vehicle graphics. Since OpenTTD was written as a remake of Transport Tycoon Deluxe, and the original version required the graphic files of the original game to run, it was a very important legal priority to create a non-pirated graphics set before someone tried to sue them. Fortunately, this was completed in the form of the base sets before such a thing happened, which are 1:1 replacements of all graphics, music and sound effects in the game with community-made replacements.
    • Because base sets must be able to be downloaded on first run or included with the game itself, all base sets are licensed under GPL v2. Fortunately this means there is not nearly so much drama compared to making NewGRFs.
  • "Game Scripts" provide custom game modes. These are also found via the content downloader.
  • Because the original Transport Tycoon Deluxe competitor AI was a cheating bastard and a hilariously incompetent transportation engineer, as of 2023 OpenTTD uses the "NoAI" system. This allows customized, community-made AIs to flourish, however many AIs in the in-game content downloader are no longer maintained or working.
  • Finally, OpenTTD diverges heavily from Transport Tycoon due to added features, and the recent addition of such features as Custom Train Stations from NewGRFs, Canals and Locks, Drive-Through Road Stops for buses/trucks and trams, Railtypes, NewObjects, NotRoadTypes, Custom Drive-Through Roadstops has made that only more so. However, such extensive features can only be added through extensive programming effort in the form of "Patches". Unlike a patch for fixing bugs, a feature patch (actual name) does what you expect but can only be applied to one version of the game (usually the latest nightly at the time), making them essentially useless unless accepted by the official version's developer team because they won't be maintained as part of the game's code updates.
    • As stated above, the fix for this was "Patch Packs" like JGR's Patch Pack, which allow more patches to be tested by wider audiences without requiring upstream (official version) code changes.
Tropes used in OpenTTD include:
  1. Jet planes will always crash more frequently at small airports, rather than only having a chance of crashing if broken down in flight
  2. Temperate, Sub-Arctic, Sub-Tropic, Toyland climates, which are all vanilla. The Japan Set. Auz Landscape. Any vanilla vehicle introduced after 1995, and any modded vehicle introduced after the point the NewGRF was released. Neon Grid Land and Space Transportation Replacement Set by Andrew350. OpenGFX Mars.
  3. If the TTO Full Conversion topic link is dead, see this footnote for backups to the [linked] [page] and [relevant] [files].
  4. In the Spiritual Successor OpenLoco, which like Locomotion starts in 1900, each time period gets era-appropriate music, Ragtime for 1900-1920, jazz and blues up to the 1950's, and then various forms of rock and roll and so on up through to trance music from the 1990s and early 2000s.
  5. At TTD's graphical scale, the Seawise Giant would be possible but would clip over the edges of canals.