Crash
In RollerCoaster Tycoon and RollerCoaster Tycoon 2, a crash is an event where at least one car of a ride explodes, often when it hits another car at a high enough speed or momentarily leaves the boundaries of its ride, such as its running rails or tower, and explodes upon contact with any surface. In RollerCoaster Tycoon 3, a crash is an event where a car leaves the boundaries of its ride.
Probability
All flat rides, like the Merry-Go-Round and Top Spin, are immune to crashes as they have predefined ride sizes that cannot be modified by the player in any way except with regards to their placement and operating modes that do not give any provisions for a crash.
Some tracked rides, such as the Car Ride, Maze and Mini Golf, are technically immune to crashes as their cars never travel at a fast enough speed to crash and/or the ride type in general does not have any operating modes that permit the possibility of a crash occurring. In addition, a handful of tracked rides, like the Splash Boats, do not crash even if they meet certain criteria that would cause a crash on other rides. On the other hand, several other tracked rides, such as the Ghost Train, Launched Freefall, most roller coaster types, and the Dinghy Slide, have an inherent possibility of crashing, although they can also be made technically crash-proof with careful design and planning as well as a proper maintenance regime.
Causes
Crashes are usually caused by a number of factors. In the RollerCoaster Tycoon games, these factors include the ride's operating mode, the design of the ride, the speed of the ride's car at the point of impact and the ride breaking down.
Operating Mode
While this is rarely the primary cause of a crash, a ride's operating mode may indirectly cause a crash, especially if said crash is caused by other factors and if it is the only reason the ride can ever crash. For instance, the Shuttle Loop design for the Looping Roller Coaster in RCT1 can crash if its operating mode is changed from "Powered-Launch Mode" to "Reverse-incline Launched Shuttle Mode" (which would cause the train to reverse out of the station and off the track), or if its Launch Speed is increased beyond the value that is set when it is built (which may cause the train to overshoot the end of the track). Without making any changes to its operating mode, however, the Shuttle Loop design is technically crash-proof as it only runs 1 train and would never leave the boundaries of its track under any other circumstances. As another example, pre-installed Launched Freefall designs are technically crash-proof unless the player deliberately increases the ride's Launch Speed beyond the value that is set when the ride was first built or sets the "Downward Launch" mode on a short tower, which would cause the car to overshoot the top piece and crash.
Ride Design
Sometimes, a ride may be designed in such a manner that a crash may occur while its cars are travelling around the track. For rides with unattached cars, such as the Bobsleigh Coaster, Ghost Train and Dinghy Slide, the ride can crash if a car flies off the track. This usually happens when the car is travelling at a high enough speed upon reaching the crest of a hill or start of a drop; for the Ghost Train, it can also happen when the car turns a corner at high speed.
It is also worth noting that the number of riders will affect the speed of the car as it travels around the track. In general, a car with more riders will travel faster than a car with no riders. Therefore, it is possible for a track design to safely pass test runs without crashing (as test runs are done without any riders on the car), only for it to crash once it opens since the additional speed caused by having riders gives the car just enough speed for it to crash. The inverse is also true—a train with a full load of riders may be able to clear some hills that a train without riders will be unable to clear. Dynamite Run from Fiasco Forest is one such example, as the trains on this coaster can complete a full circuit only if they have a full load of passengers on board.
In RCT1 and RCT2, most rides with unattached cars will crash if a car enters the top of a hill at a speed exceeding 31mph (50km/h) or the start of a drop at a speed exceeding 40mph (64km/h). Of the reminder, the Flying Turns will crash if a car enters the top of a hill at a speed exceeding 28mph (45km/h) or the start of a drop at a speed exceeding 30mph, while the Side-Friction Coaster will crash if a car crests a hill at a speed exceeding 25mph (40km/h). A Ghost Train or Haunted Mansion Ride car will crash if it enters a sharp curve at a speed exceeding 14mph (23km/h) or a medium curve at a speed exceeding 19mph (31km/h). In RCT3, the Bobsleigh Coaster can also crash if its cars careen off the side of the track while entering a corner or, in rare cases, travelling through alternating left and right banked turns at a high enough speed.
The Reverse Freefall Coaster—and, in RCT1 and RCT3, the Air Powered Vertical Coaster—and their variants, despite having cars that are held in place by the ride's running rails, can be constructed as incomplete circuits, so their cars can still crash if they travel at a high enough speed to overshoot the end of the track.
Both the Dinghy Slide and Water Coaster rides are known for inexplicably crashing in RCT1 and RCT2 if a car travels down a drop with a height exceeding one steep drop.
In RCT3, if an Observation Tower is built without a top piece (i.e. only the station piece is built), the tower's passenger car will fly off the tower section upon reaching the top and crash after a while.
Speed (on Impact)
In RCT1 and RCT2, a crash can happen when the car of a ride is travelling too fast when it collides with another car on the same ride. Similar to a ride's operating mode, the speed of a car on impact may cause a crash due to other contributing causes, such as the ride's design or a breakdown.
It is not possible for rides to crash in RCT3 due to impact with other cars; cars that collide at high speed will ricochet off each other harmlessly at a much lower speed.
Like crashes caused by ride design, the speed of a car is influenced and usually increased slightly by the presence of riders. However, unlike crashes caused by ride design, all rides that have an inherent possibility of crashing in RCT1 and RCT2 will crash if two cars on the ride collide at a combined speed of 30mph (48km/h) or more.
Breakdown
It is important to note that a ride that exhibits other possible causes of crashing may operate normally without incident for many years as long as it does not experience specific breakdowns. Therefore, a ride breakdown is sometimes indirectly responsible for a ride crashing because it drastically increases the chances of the ride crashing due to other causes. One of the most notorious examples comes from any ride design where the car enters the station exceeding 30mph (48km/h) while another car is at the station. Under normal operations, the car that enters the station will be slowed down safely by the station platform's brakes the moment it enters, and it would fetch up behind the other car in the station without incident. However, if the ride experiences a "Station Brakes Failure" or "Brakes Failure", the car will not slow down as it enters the station and will crash the moment it collides with the other car that is already in the station as it is travelling at a speed exceeding 30mph at the time of impact. As an example, most pre-installed and pre-built track designs in RCT1 are highly prone to crashing due to breakdowns, especially if they run more than one car. More rarely, crashes from restraints stuck closed breakdowns can occur if the affected train is partially sticking out of the back end of the station and another train attempting to enter the station collides into the affected train at a speed higher than 30 mph (48 km/h) and subsequently explodes. The affected train can even be over the brakes or block brakes, preventing other trains from slowing down before crashing.
Effects
The effects of a crash can be split into two categories: immediate effects and delayed effects.
Immediate Effects
The moment a crash occurs, the ride that crashed will be closed immediately without any player input and a message will appear in the message window stating that the ride has crashed. Because the ride is closed automatically, any guests queuing up for the ride will exit the queue.
In RCT1 and RCT2, there are a few additional effects: the ride window for the ride that crashed will pop up, with the camera view automatically focusing on the car that crashed or is in the process of crashing, any riders on the ill-fated car are immediately removed from the park, and a second message that follows after the initial message stating that the ride has crashed will tally this number of riders as the number of guests that died due to "an accident" on the ride. There will also be an endless cloud of steam rising from the crash point.
In RCT3, a crash is considered to have happened the moment the first car leaves the ride boundary, as opposed to the first car exploding after leaving the ride boundary in previous games, although any cars that do leave the ride boundaries will bounce around the surface they impacted (or in the case of water, sink slowly) for a few seconds before actually exploding. Ride vehicles can also run over peeps, injuring them and sending them flying in the process; the faster the vehicle, the farther the peeps will be displaced. Peeps and staff will additionally be blown away should they be close to a ride vehicle that explodes. After being knocked down by ride vehicles, peeps will get back on their feet. Peeps will also complain when a crashed ride vehicle goes near them, even if they are on a ride, although peeps that are on rides or swimming in a Pool Complex cannot be injured by crashing/exploding ride vehicles. Ride vehicles immediately explode if they leave a ride track that is completely underground.
Delayed Effects
Some of these delayed effects will occur almost directly after the immediate effects of the crash, while others will only be more pronounced in the long-run.
As word goes about that a ride in the park has crashed, the ill-fated ride will suffer a massive drop in popularity. If any guests die as a result of the crash, the drop then extends to the entire park in general, with the park's Park Rating taking a massive hit and a significantly increased rate of guests leaving the park. Park attendance also falls as a result, with fewer guests entering the park.
The ill-fated ride will have a "crash history" for about four months, during which most guests visiting the park will refuse to ride it. The ride itself can be "reset" by manually closing it a second time, which causes the steam issuing from the crash point to disappear completely, and it can then be re-opened as per normal. It will regain its natural popularity after its crash history expires.
In RCT3, the occurrence of a crash may also cause the park to be given the "Most Dangerous Park" and "Most Criminally Negligent" negative awards, which both incur a fine, especially if too many peeps get injured in the process.
Prevention
Crashes are preventable on most non-roller coaster rides and roller coasters with unattached cars by simply designing them well. Make sure that vehicles don't crest hills too quickly on rides where the vehicles are unattached, and always test ride designs with an incomplete circuit layout, such as powered launch and reverse-incline launched shuttle loops.
In RCT1, it is difficult to completely prevent crashes caused by the "Station Brakes Failure" breakdown, crashes caused by a stall as the result of a "Safety Cut-out" breakdown, or crashes caused by a train partly sticking out of the station's back end due to the "Restraints stuck closed" breakdown. The easiest way to prevent such crashes is to remove all but one car/train from the ride, though this reduces the number of guests that can ride at once, and thus lowers the ride's profitability. Adding "brake runs" (sections of track filled with brakes) can also reduce the speed of the cars midway through the track or right at the end, giving the cars less momentum and possibly preventing a crash; an additional effect of having brake sections on the track is that they reduce the chances of a "Station Brakes Failure" breakdown occurring. One way to keep the duration (and, in the short-term, likelihood) of breakdowns low is to set the inspection time for rides to "Every 10 minutes", and placing a mechanic right at the exit of each ride with a patrol path on the exit of the ride. This reduces the rate at which the ride's reliability drops, and in the event of a brakes failure, the mechanic is right there to quickly respond and fix the ride. A different way to prevent crashes is to make sure that there will only ever be one train in or near the station or on lift hills by adjusting the ride's minimum and maximum wait times. The ideal amount of minimum and maximum wait time varies per ride, and there are no universal safe values or easy formula for safe times; the best way to find out good times is to experiment. Another option is to design the ride such that its cars always traverse hills and drops and approach and enter the station at safe speeds even during breakdowns, eliminating any chances of a crash.
RCT2 adds block brakes on several roller coaster designs, which can drastically reduce the possibility of crashes on such designs. Block brakes separate the track into "sections", with each block brake on the track acting as the divider between sections. When a car is still travelling around one section, the block brake that divides it from the previous section of track will attempt to completely stop the next approaching car until the car in front has completely passed the next section, failing which it will still slow down the approaching car significantly. Using a block brake system allows many cars to operate on the track without having to build a long station platform to accommodate all of them. In addition, constructing at least one block brake on a ride and setting it to "Continuous circuit block sectioned mode" removes any possibility of a "Brakes Failure" breakdown happening on that particular ride. The only major downside of using block brakes is a small decrease in the ride's excitement rating.
In RCT1 and RCT2, a crash does not actually happen until the first car explodes. This makes it possible for players to avert a crash at the last possible moment by pausing the game while a car is "Crashing!" and resetting the ride by closing it twice, which automatically removes all cars on the track and causes all guests—including the guests on the car that was originally about to crash—to alight from the ride without incident.
In RCT3, peeps cannot die under any circumstances. In addition, cars that impact each other at high speed no longer explode, instead bouncing away from each other upon impact—this completely removes all possibility of a crash arising from two cars colliding with each other at high speed. Crashes can still occur, however, if the train leaves its ride boundary either by overshooting the end of the track (for incomplete circuits) or by flying off a corner while attempting to negotiate it at high speed (for rides with unattached cars). The penalties associated with a crash can be avoided by testing rides before opening them.