The book that River Song will write, under the name Melody Malone, after the events of this adventure lets them peek ahead. From it they learn where Rory has been sent by the Weeping Angels but also that they break something because they read it in the book, which turns out to be River’s wrist.
This was touched upon in the story that introduced River Song ‘Silence in the Library/Forest of the Dead’ where the Doctor prevents Donna from finding out about her future and River prevents the Doctor from peeking at her diary, warning of spoilers. It is also the curse that the Doctor lives with in season 6, knowing that he is fated to die in Utah, 2011.
The 4th Doctor book ‘Festival of Death’ does an excellent job of exploring this idea with the main characters arriving at the end of their adventure and learning that the Doctor saved the day by sacrificing his life. The rest of the book is spent gradually bringing the characters to that point.
Other time travel fiction has explored this concept as well. ‘Somewhere in time’ has Christopher Reeves’ character Richard Collier deliberately find proof that he’ll travel in time. ‘Time Crimes’ (or ‘Los Cronocrimenes’) has the main character Hector learn about the actions of his future self, which still doesn’t dissuade him from trying to change events.
This can be explored in your own adventures. Player characters may specifically use time travel to find out the future in this manner. Just how they do this determines what attribute and skill are used.
Awareness should be used if observation is a factor, such as finding traces of your presence in the past. Ingenuity could be used if the character has come with a clever way to find out the information. Presence would be appropriate if the character is getting the information from witnesses.
The convince skill is useful if the witness doesn’t want to reveal what they saw. Technology and Transport are appropriate if they are using time travel technology to locate the information.
The difficulty should be based on how much information they are trying to find, how public the events were and how distant they currently are from the time period they are trying to learn about.
On a 0-3 they learn what they wanted but also something that puts them at a slight disadvantage which they can’t avoid. They could learn that they faced an opponent alone, that a vital piece of equipment failed or was lost or that one of them is injured.
No attempt to change this will work and may even hasten the fate they were trying to avoid. Their frantic instance for an ally to come with them might put their friend off or they might give them the wrong directions, fearing their sonic screwdriver will fail them they swap it for a new version only to find it is that device that fails or their own concern about the injury they will suffer causes them to trip and fall, leading the injury.
On a result of 4-8 the required information is found. They find out where the villain was hiding, what was used to defeat him or whatever else they were looking for. The players have gotten off easy.
On 9+ the characters have not only found what they were looking for but something extra. They might learn about a lightening strike which they can harness, an accident which will close a road or something that can give them an edge. You may wish to give the players a story point that they can use later to represent the extra piece of information that they learnt.
On a result of –1 to 3 the player characters didn’t find out what they were hoping but still discovered something useful. This could be a clue or a tip that aides them in their future. It is at least something for them to go on.
A –4-8 means that the characters didn’t learn anything useful but at least they haven’t found out anything unpleasant. Their future is still a blank slate.
A -9+ means that not only have they not learnt what they were looking for but they’ve discovered something very bad. They could learn that they fail to defeat the bad guy, or that they or someone they know is going to die.
Worse still this becomes a fixed point in time. Potentially they could find a way to change it but they run the risk of creating a paradox. Unless care is taken the resulting energy could destroy the local area.
Characters are therefore playing a dangerous game by looking ahead. Players should understand the risks involved before the try to find a spoiler. Of course they might not be looking for it intentionally.
An adventure could begin with the characters finding a books, film or painting that indicates their presence in the past or meet someone who is all to happy to be reunited after their big adventure.
This gives the player characters a compelling reason to travel back to this event, to find out what their involvement was. Portents of doom should be used to add tension to the adventure but not lock the characters into an unpleasant fate.
Ordinary people, or at least those without time travel, might still learn about their future. A careless time traveller might leave a history book, a newspaper from the future or other artefact that allows others to know what will happen. They might even let slip some vital information that brings with it the curse of foreknowledge. The PCs will have to find a way to rectify the situation without creating a paradox.
You may also wish to provide the knowledge of the future in an enigmatic way. Cryptic verse might give the player characters hints but the true meaning is only revealed in retrospect. This can give them just enough to work on but not enough to create a fixed point in time.