The new D&D books have rules for chases but, reportedly, they’re a bit overcooked. There are simple ways to conduct chases for old-school gaming that still have all the fun.

Evasion

First determine the distance between the two groups, as with of any encounter.

• If a group of creatures is not detected by another group in a wilderness or urban setting, it can nearly always evade the other group (and avoid a chase) by keeping a low profile and avoiding it. (Altho, on wide-open terrain, this is probably not possible.)
• If the group is detected (which is up to your assessment of the circumstances… or fate), have the least stealthy of the evaders roll a stealth check (at a distance or in a city, the rattle of heavy armor is immaterial). If successful, they lose the other group in the undergrowth or city streets; otherwise, the other group may pursue them.

You may rule that a character with tracking skill or creature with hunting instincts can roll a check to pick up the trail again. The heroes are unlikely to fool a determined predator for long by hiding behind a rock.

Pursuit

To conduct a chase on foot or conveyances (horseback, carriage, flying carpet, etc.), first consider the setting. On a wide-open grassland, moor, tundra, desert, or cloudless sky, the only thing that matters is speed, since there’s the pursued can’t lose the pursuers behind a solitary tree. But in other environments, determine the starting distance between the pursuers and the pursued.

Starting Gap

A typical starting gap would be 15 to 25 units. The measure of the units (feet, yards, tens of yards) isn’t important, because the chase isn’t very linear. Even if the pursued are aiming for some specific safe destination, the chase will likely zig-zag from here to there as the pursued try to lose the pursuers. Therefore, the chase doesn’t take place on a map.

Roll up Three Routes

To start, roll three d20s for three possible routes. The pursued group chooses one of the routes. Choosing a low difficulty means you’re running to more open ground (maybe because you’re faster), while choosing a high difficulty means you’re deliberately choosing a route with tricky terrain or obstacles (maybe because you’re more agile). See the table below for what each difficulty might mean.

Chosen Difficulty	Forest, Swamp	Village/Town/City	Rocky Terrain
1-4	Open ground*	Open ground*	Open ground*
5-6	Duck low tree branch**	Duck low-hanging sign or laundry line**	Duck a rock overhang or tree branch*
7-8	Jump tree roots	Slippery mud/manure	Precarious rocks
9-10	Slope (up or down)	Stairs (up or down) or dodge a cart	Slope (up or down)
11-12	Jump a fallen log	Dodge a person	Slippery rocks
13-14	Dodge an animal	Slip thru a closing gate or jump a fence	Gravelly slope
15-16	Cross a stream	Dodge stray livestock or group of people	Scatter sheep or goats
17-18	Ford a small river or run thru a thicket	Dodge passing carts or climb a fence	Ford a small river
19-20	Unforeseen ravine	Herd of livestock or dead end alley	Cliff/bluff or obstructing boulder

* If the movement rate of the pursued is higher than that of the pursuer, add the difference to the gap; otherwise, subtract the difference.

** If the movement rate of the pursued is higher than that of the pursuer, add half the difference to the gap; otherwise, subtract half the difference.

Each turn, each group rolls to check the current difficulty. In a foot chase, characters can apply a dexterity modifier and any sporting or athletic skill in your system. The pursued get +2 to the check, because they chose it to suit their abilities. Each turn is one combat round.

• If you succeed on a check, you get thru the terrain or past the obstacle without much difficulty. Roll 1d6 to extend the gap (if you’re the pursued) or close the gap (if you’re the pursuer).
• If you fail a check, it costs you 1d6 gap units to get thru the terrain or past the obstacle. The GM should narrate it (“You trip over the log”, “You get grabbed by someone and have to shake them off”, “You fall down and scramble to your feet.”)
• If you roll a natural 1, you get hung up and give the opponent the effects of a natural 20.
• If you roll a natural 20, you get an unexpected chance to lose the pursuers (make a stealth check) or cut off the pursued (close the gap by 2d6).

Ending the Chase

The chase continues until one of the following happens:

• The pursuer closes the gap to nothing and can physically stop the pursued.
• The gap widens enough that the pursuer gives up.
• The pursued succeeds in losing the pursuer.