A simple mechanism
This article suggests a simple but flexible and exciting method for roleplaying pursuits. The idea is to translate the excitement of the chase into a mechanic. Therefore, this mechanic should be used with exciting chases. It should be used when adrenaline is pumping, not during scenes where the pursuers are methodically following a trail of a prey long out of sight.We will be using the characters' Move scores (M), modified by all the talents that matter, and the characters' Agility bonus (Ab). This bonus is computed in the same way as Strength and Toughness bonuses. Further, one d10 is being used. For each party we will be calculating a Pursuit score. Yes, I know that it sounds complicated, but in practice it isn't. Trust me.
A pursuit will take several rounds, and will begin with a situation in which the quarry gains a lead. This lead is expressed numerically, default being 10. This lead is also the starting Pursuit score of the quarry, while the pursuants start with a score of 0. Each round, both parties make a pursuit roll; they roll a d10 and add their M and Ab. This total is added to their Pursuit score. At the end of the round, the difference between the fleeing party and the pursuing one is checked. If the pursuit difference is 0 or lower, the pursuers have caught up with their victim; if the difference has passed a treshold (default being 20), the victim has escaped.
While this sounds like a lot of computations each round, in practice you don't look at the totals and such; instead, you directly compute the difference. Start with the fixed values of the pursuit roll; the M and Ab. If this score is different for pursuer and pursuant, the party with the highest score may apply the difference as a bonus to his pursuit rolls. Then both parties roll a d10 each round, bonus being applied, and the difference between those two rolls is added to or subtracted from the score of the previous round.
Example: Bruno chases Albert, Albert having a head start of 10. Albert has M4 and Ag 47, Bruno has M4 and Ag 34. So for Albert M+Ab is 8, for Bruno it is 7. Albert has a +1 advantage each round.
The first round the dice are rolled. Albert rolls a 7 and adds his +1 bonus for a result of 8. Bruno rolls a 4. The difference between the two rolls is 4, and this difference is added to the head start. The pursuit difference is now 14.
Second round, Albert rolls a dismal 1, adding his bonus for a meagre result of 2. Bruno rolls a 9, so he gains seven points. The pursuit difference has decreased to 7, and the chase goes on.
Overthrow the apple cart
Instead of simply fleeing or pursuing, the parties can perform an action in a round. The person fleeing can do things like overturning a market stall, climb a wall and continue his flight over the rooftops, or jump a chasm, in order to give his pursuers a harder time. During that round, instead of rolling M + Ab +d10, the player makes a normal task resolution roll. Alternatively, if the action can be done while running away (such as knocking over a ladder to create a quick barricade, or flinging shillings around in the hope that the ensuing crowd will block the pursuers), a negative penalty on the pursuit roll will be enough. If the action succeeds, the pursuing party will have to make a roll too, to resolve the difficulties that they are faced with.Similarly, pursuers can make an action instead of simply run after their quarry. They can stop to ready their crossbows, for example, or mount a horse to make better speed. Or they can get on the rooftops, to get a better view of where their prey is going and to avoid the crowded streets. Like the other party, they sacrifice their pursuit roll and do their action, or they get a negative modifier on their roll.
It is still a role playing game
Narrative is still important. The GM should take care that the whole pursuit does not come down to only a game of dice rolling. Each round should at least contain a short description of the situation. These should inform the players of their surroundings and special circumstances. "The thief is now running out of the market hall, into the high street." "The street is going downhill now, and you run with breakneck speed over the slippery cobblestones." "When you turn the corner, you see that this is a dead end street." Don't give descriptions that are too long, or you will lose the excitement and the sense of urgency. The PCs have no time to get a detailed view of the surroundings anyway.If the GM has an idea that a chase scene will be happening in the next session, he can prepare for that. He can think of which areas the chase will be in, and prepare descriptions. Sometimes during a chase he can prepare special events. The PCs being on horseback, fleeing town while pursued by the military, get into a street where children are playing, for instance. Or, when they are pursuing their quarry through the forest, they run into a goblin hunting party. If the GM knows about the chase in advance, he can prepare these little difficulties and surprises for the players.
Alternative situations
Above, we set the default lead at 10 and the escape treshold at 20. These figures are not directly translatable into yards or other distances; instead, they are purely an abstract game value. In a crowded market place, the prey is perhaps only a few feet away from the hunter, where in vast grasslands and gently rolling hills, with both parties on horseback, it may be a distance of dozens or hundreds of yards. The values given make for a chase that generally won't be too short or too long, and where both parties have equal chances.The default lead is 10. The GM can change this number if he feels that the pursued party has not gotten a good head start, or if the other party reacts too late to the prey fleeing. Likewise, the default escape treshold is 20, but the GM can change this according to circumstances. Situations where escape is easy, such as crowded places or a mist limiting visibility should bring the escape treshold down, while circumstances that favour the pursuers (wide, open plains with clear view of the quarry) should raise that treshold. The treshold doesn't have to stay the same during the whole chase either. When circumstances or surroundings change during the chase, the GM might adapt the value of the escape treshold to reflect it. Chasing someone through broad lanes is easier than following him through a maze of back alleys.
Sometimes the escape treshold is not the limit. For instance, the PCs are chased by a vampire and just have to stay out of his reach until the sun comes up. In such a case, the GM should determine at which round the sun will come up, and set up a chase for that many rounds.
Another situation is the one where the prey is safe once it crosses a border - the PCs still being chased by that vampire, and he cannot cross running water. In this case there is a bit more bookkeeping. The GM sets the distance to the river in pursuit points (say, 200 PP). Each roll, both parties have to compute their totals (M + Ab + d10 + pursuit score of the last round). If the PCs reach 200 points before the vampire has gotten to them, they have reached the safety of the river.
And there is the situation where there is no chase, but instead a race to determine who first gets to the idol, or past the finish line, or whatever. This is being dealt with similarly to the previous situation. The GM sets the distance in pursuit points, and all parties roll and compute their total. The party who gets over the total first, wins. If more than one party do in the same round, the one with the highest total snatches away victory just an instance before the other.
Or there are complicated chases, where A follows B, who follows C, and so on. The mechanic still works the same, with each party concentrating on the distance to the party he is pursuing. In one of my games the party was chasing a thief. The thief being swift, he had quickly outrunned Alfred, but Bernhard still had him in his sights. Alfred, not seeing the thief anymore, was just pursuing Bernhard - if he could catch up with him before Bernhard had lost track, he would get the thief in his sight again.