Evasion and Pursuit

From OSE SRD

In the Dungeon

Evasion

Compare the two sides’ movement rates:

  • Fleeing side faster: The evasion automatically succeeds, unless the fleeing side is forced to stop.
  • Fleeing side not faster: A pursuit occurs.

Pursuit

Time: Is measured in rounds (see Time, Weight, Movement).

Running: Each side is assumed to be running at full speed (see below).

Line of sight: Most monsters will not continue a pursuit if the characters get out of the monster’s range of vision.

Dropping treasure: If the monsters enjoy treasure, there is a 3-in-6 probability that they will stop pursuit to collect any treasure the characters drop.

Dropping food: Hungry or less intelligent monsters may stop pursuit if characters drop food (3-in-6 chance).

Obstacles: Burning oil or other obstacles may also slow or stop a pursuit.

Running

Movement rate: During a pursuit, characters run at their full movement rate in feet per round.

Mapping: Is not possible while running.

Exhaustion: Characters become exhausted after running for 30 rounds.

Effects of exhaustion: A -2 penalty to attacks, damage, and Armour Class.

Resting: The penalties for exhaustion last until characters have rested for three full turns.

Waterborne

Evasion

The chance of evasion is determined by the difference between the two sides’ movement rates, listed in the table below.

Success: If the evasion roll succeeds, the pursuers cannot attempt to catch up with the fleeing side until the next day—and then only if a random encounter roll indicates an encounter.

Failure: If the evasion roll fails, a pursuit occurs.

Waterborne Evasion Chance
Fleeing Side’s Movement Rate
(Compared with Pursuer’s)
Chance of
Evasion
Faster than pursuer 80%
0’–30’ per round slower than pursuer 50%
31’–60’ per round slower than pursuer 40%
61’–90’ per round slower than pursuer 35%
91’–120’ per round slower than pursuer 25%
121’+ per round slower than pursuer 10%

Pursuit

Time: Is measured in rounds (see Time, Weight, Movement).

Initial distance: The two sides begin a pursuit at normal encounter distance (see Waterborne Adventuring).

Closing in: The distance between the two sides decreases by the difference between their two movement rates each round (a minimum of 30’ per round).

In the Wilderness

Evasion

The chance of evasion is a percentile roll. If the percentile evasion roll fails, a pursuit occurs. Surprise (see Encounters) determines the chance of evasion:

  • No surprise: If neither side is surprised, the chance of evasion is determined by the relative size of the two groups. (The chances are in favour of the smaller group, as larger groups cannot move as fast or as quietly.) The Wilderness Evasion Base Chance table indicates the base chance of evasion.
  • Surprised side: May generally not evade. The referee may rule that environmental conditions give a small chance of evasion even when surprised (as above). For example, dense woodland may give a surprised side a 10% chance of evasion.
  • Surprising side: If one side has surprised the other, the side with surprise may evade automatically—the surprised side is not even aware that the encounter occurred.
Wilderness Evasion Base Chance
Fleeing Group Size Chance of Evasion by Number of Pursuers
1–4 1 pursuer: 50% 2–3 pursuers: 70% 4+ pursuers: 90%
5–12 1–3 pursuers: 35% 4–8 pursuers: 50% 9+ pursuers: 70%
13–24 1–6 pursuers: 25% 7–16 pursuers: 35% 17+ pursuers: 50%
25+ 1–10 pursuers: 10% 11–30 pursuers: 25% 31+ pursuers: 35%

Evasion Modifiers

One side twice as fast: If the pursuing side’s movement rate is double that of the other, the chance of evasion is decreased by 25%. If the fleeing side’s movement rate is double that of the other, the chance of evasion is increased by 25%.

Environment: The referee may modify the probabilities based on the conditions and environment. For example, in a densely wooded area, the chance of evasion may be increased by 25%.

Minimum chance: The chance of escape is always at least 5%.

Pursuit

The following procedure is followed, day by day, until the pursuit is over:

  1. The fleeing side moves in a random direction, determined by the referee (no mapping is possible).
  2. If the pursuing side’s movement rate is greater than that of the fleeing side, there is a 50% chance of it catching up. If the roll succeeds, the fleeing side has been caught; the pursuit is over. Otherwise, continue to step 3.
  3. The fleeing side must decide whether to continue fleeing. If it decides to continue, it may make another evasion attempt (see above). If the attempt to evade fails, return to step 1. If the fleeing group decides to stop fleeing, it is caught (the pursuit ends).