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Sandbox Adventures

Adventure And Encounter Design

Source Galaxy Exploration Manual pg. 138
Sandbox adventures differ from traditionally structured adventures, such as Adventure Paths, in that the settings are open rather than structured, they reward improvisation and creativity in different ways, and the emphasis is on verisimilitude instead of narrative.
Ultimately, the sandbox is a site, not a story. It should have multiple means of entry and progression so the PCs can decide for themselves how they want to enter and work their way through it. To make these decisions, the PCs need information, so they should be able to acquire it within your setting—perhaps by observing a site, researching it on the infosphere, or simply asking their contacts. If the PCs discover three doors within a set of alien ruins, the choice between them is significant only if there’s some way to differentiate the doors from one another. If they know one door has an evocation aura, one door is filled with a nanite mist, and the last shows signs of a large carnivore sleeping beyond, your PCs can now make a meaningful choice based on their own preferences and strengths. Similarly, the interior of the site should have multiple paths, and it should be possible for the PCs to withdraw from the site completely and come back later. One of the hallmarks of a sandbox is that the PCs can explore it over multiple sessions, so they can explore, retreat to their home base, and return to explore some time—perhaps even a long time—later.
As a GM, you have a unique opportunity in sandbox adventures: you get to create problems and let the players find workable solutions! In other words, don’t decide ahead of time that there’s only one way to bypass a given obstacle. Instead, give the players enough details about the obstacle for them to come up with creative solutions. Then, allow those solutions to have at least a chance of success (if they are reasonable and move the story forward). For this type of encounter to be successful, you need to be open-minded. Sure, that defrex guarding a siccatite mine is probably violent and hostile, and the PCs will likely fight it, but perhaps they can find a way to sneak around it, lure it off, or even befriend it—after all, it’s an animal and that means the xenodruid mystic can talk to it. Your preparation will include some thought into the various approaches the PCs might take, but you don’t need to overthink it. Let the PCs surprise you. While this is true even in prewritten adventures, it becomes much more common and relevant in open-ended adventures.
The Core Rulebook describes how to create encounters that are an appropriate challenge for your PCs, but in a sandbox adventure, the PCs might encounter threats far above or below their ability. This realism makes the adventure feel more alive and adds a sense of unpredictability to the campaign. It’s important to signpost especially deadly encounters so the PCs can choose whether to go forward or withdraw. After all, if 3rd-level PCs don’t know they’re walking into the lair of a CR 14 deh-nolo, or even just that something especially dangerous is down a particular tunnel, they’re not to blame when all the whole party is killed. But if the PCs have heard rumors of corpses found in this area with their brains missing, they have a lead they can pursue to gain an idea of what they’re in for.
Random encounter tables can be useful in sandbox games. A good random encounter table reinforces the themes of the adventure site, contributes to in-world verisimilitude, and can even reveal clues the PCs would otherwise miss. Most of the encounters on such a table will be hostile, but others might be neutral observers or even potential allies. This book includes many tools to help you create these tables, particularly the inhabitant and adventure hook tables in Chapter 2’s biome and cultural attribute sections. See Example: Alqet Encounters below for an example of an encounter table.
Above all, your adventure should challenge both the players and their characters. The PCs should have to use all their best abilities both in and out of combat to be successful, and the players should be rewarded for clever tactics, preparation, creativity, and excellent roleplaying. Let the players call the shots while you throw obstacles their way. As with any adventure, when your players solve or simply avoid one of your encounters through means you didn’t anticipate, such as the use of an ability, don’t be tempted penalize them or block the use of their ability. Instead, congratulate them on their ingenuity and let them enjoy the victory! After all, there’s a lot more to explore, and you have many more difficult challenges in store for them.

Example: Alqet Adventures

Source Galaxy Exploration Manual pg. 138
Joan’s players will make a team of archaeologists for their characters, but that leaves a lot of latitude for individual concepts. They might be technical support, security guards, field agents, or mystics looking for traces of ancient alien gods. There’s a large ruin on Alqet V, which the PCs know about before the campaign begins. With a little investigation—and a poker game with Evan—the PCs can learn of traces of life on the toxic Alqet IV and a ruined starship in the rings of Alqet II. Each of these is a smaller sandbox adventure site nested inside the larger sandbox that is the Alqet system. The PCs are unlikely to investigate some of the other adventure sites in the system initially, either because they don’t know about them yet (the other planets in the system) or because the sites are too dangerous (the high-magic zone on Alqet II).
Joan begins with the big site on Alqet V, which she decides is in a swamp and includes nine crumbling pyramidlike structures. These buildings correspond to the nine planets in the system, and each building will have clues pointing to ruins on each corresponding world. Because the pyramids are in the open, half sunk into the marsh, the PCs can investigate them in any order and withdraw when they want to. But Joan knows some of the pyramids are more dangerous than others. She puts a shadowy cloud of necromantic energy around one of them to indicate it’s been taken over by a Necrotocracy team, buries a few pyramids deep into the marsh, and surrounds another pyramid with Interstellarium gun emplacements. PCs are more likely to explore easy sites before hard ones, and if some of the pyramids are difficult to get to, the PCs will most likely put off exploring them till later, at which time Joan can prepare them fully.
This still gives the PCs several pyramids to choose from, however, so Joan prepares a basic map she can show the players and gives the remaining pyramids distinguishing features. She’s decided one of the PCs will win this map in one of Evan’s poker games; with it, the PCs can decide which of the pyramids they intend to explore in their next session, and Joan can focus her efforts on developing the site they choose.

Example: Alqet Encounters

Source Galaxy Exploration Manual pg. 139
Joan is making a random encounter table for the pyramids on Alqet V; she expects the PCs to first come here when they are 1st or 2nd level. She wants to include encounters that point the PCs toward threats elsewhere in the system, encounters the PCs can avoid, and some they would wisely flee.
1 2 squoxes, hunting for food to bring home to their young. They avoid the PCs unless somehow communicated with. (Indifferent) 1/2 Alien Archive 2 118
2 1d3 anacite wingbots, conducting maintenance on the facility. They ignore the PCs unless interacted with. (Unfriendly) 1 Alien Archive 11
3 1 assembly ooze that went rogue. (Hostile) 1 Alien Archive 16
4 2 barathu scientists, who came here exploring but are now lost and terrified. They are noncombatants and flee or cower in fear. If the PCs get them out of the facility, they have a shuttle nearby and invite the PCs to Morpheus Station. (Indifferent) 1 None
5 1d6 mutated worms, products of strange magical energy in the ruins. (Unfriendly) 2 Use asteroid louse, Alien Archive 2 132
6 1 medium earth elemental, left behind as a guardian by whoever built these ruins. (Hostile) 3 Alien Archive 46
7 1 Interstellarium soldier, the last survivor of her squad, now just trying to get out alive. Though lawful evil, she will work with the PCs if they agree to help her get back to the Interstellarium pyramid. (Indifferent) 3 Use Aeon Guard, Alien Archive 6
8 1 Necrotocracy techromancer looking for lost technology. Flees the PCs and attempts to reunite with his ghoul minions, below, before hunting down the PCs. (Unfriendly) CR 3 Use bone trooper technomancer, Alien Archive 2 22
9 1d3 ghouls, servants of the techromancer, scouting for objects of interest and corpses to eat. (Hostile) CR 3 Alien Archive 2 60
10 1d6 cocooned akatas. If moved, a cocoon has a 25% chance to break open and an akata emerges. (Hostile) CR 4 Alien Archive 2 8