Guest Pathfinding

Lore & Background

In the world of RollerCoaster Tycoon, the park is a living organism whose circulatory system is the path network. Guests arrive at the park entrance with a list of desires—thrill rides, gentle coasters, a hot dog, a drink—and the pathfinding engine is the quiet decision-maker that translates those desires into a physical route across the tile grid. It does not 'see' the park the way a human would; it sees a graph of connected walkway tiles, each one a node, each adjacency an edge. The shortest walkable route wins.

What makes the system feel alive is its interaction with guest psychology. A guest who has just experienced a violent drop on a steel coaster will want a soft drink; the pathfinder will route them to the nearest drink stall, but only if a path actually connects their current tile to that stall's entrance tile. If the player has built a dead-end or a one-tile-wide bottleneck, the guest will queue, wait, and eventually lose patience—contributing to the park's overall guest satisfaction score. In this way, pathfinding is not merely a routing algorithm; it is the bridge between the player's layout choices and the emotional experience of every individual visitor.

The system also interacts with the queue system. When a guest reaches the entrance tile of a ride, they transition from 'pathfinding' to 'queuing' mode, lining up along the designated queue tiles. The pathfinder's job is done for that leg of the journey, and it will re-engage the moment the guest exits the ride and needs to find their next destination. This hand-off between pathfinding and queuing is where many of the game's congestion problems originate: a narrow exit path can create a traffic jam that backs up into the ride queue itself.

In Their Own Story

The afternoon sun hung low over the park, casting long shadows across the freshly laid concrete paths. Gerald, a guest in a faded red cap, had just stepped off the 'Thunderbolt' coaster and felt his ears still ringing. He wanted a lemonade. He wanted it badly. His eyes scanned the crowd, but his feet—guided by an invisible hand—began walking.

He turned left at the first junction, then right at the second. The lemonade stand was, he was sure, just ahead. But the path looped. He walked past the stand. Walked around the back. Walked past it again. His companion, a woman with a stroller, sighed and muttered something about 'the layout.' Gerald kept walking. The algorithm had chosen a route, and the route was a circle. He would pass the lemonade stand eleven more times before the path finally, mercifully, led him to its door.

He bought the lemonade. It was warm. He did not care. He was thirsty, and the path had, at last, delivered.

Reader's Guide

The pathfinding engine treats the park as a graph: every walkway tile is a node, and every pair of adjacent walkway tiles shares an edge. When a guest selects a destination (a ride entrance, a food stall, the exit), the system searches this graph for the shortest walkable route. It does not consider terrain outside the path network—grass, water, and ride structures are simply impassable. This means the 'shortest path' is the shortest path *through the tiles the player has built*, which is why a winding path can be the only route even if a straight line across the lawn is geometrically shorter.

Path width matters more than most players expect. A one-tile-wide path creates a natural bottleneck: two guests walking in opposite directions must yield, causing micro-congestion that cascades. Two-tile-wide paths allow opposing traffic to flow simultaneously. In RCT2, the system also factors in 'path flags' that mark queue tiles, entrance/exit tiles, and decorative paths, which can subtly alter how the algorithm weights connections.

Practical strategies: First, always ensure every ride entrance and exit connects to the main path network—dead-end paths are the number-one cause of guests getting stuck. Second, avoid long circular loops without a 'break' tile (a tile that connects the loop to a radial path), because the pathfinder may select the loop as part of the shortest route, sending guests around and around. Third, place popular destinations (drinks, restrooms) adjacent to high-traffic path junctions so the pathfinder routes guests there naturally. Fourth, when redesigning a section, temporarily remove the old paths before laying new ones; overlapping path tiles can create ambiguous connections that confuse the routing.

Finally, remember that staff use the same pathfinding system. A janitor or mechanic who cannot reach a broken ride will simply stand idle, which is why path coverage for maintenance is as important as path coverage for guests.

Did You Know?

• Guests in RollerCoaster Tycoon cannot walk across grass, water, or any non-path tile—no matter how short the distance—so a single missing path tile can strand a guest indefinitely.
• The pathfinding system is shared by guests and staff; a mechanic who cannot pathfind to a broken ride will stand idle and the ride will remain closed until the path is fixed.
• In RCT1, the pathfinding algorithm is notably simpler than in RCT2, which is why circular path loops are more likely to trap guests in the first game.
• A guest's 'destination' is chosen before pathfinding begins: the AI first decides *where* to go based on interests and current needs, and only then calculates *how* to get there through the tile graph.