OSR Chase Procedure

2026-06-20

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Tags: OSR Be Not Afraid Mechanic Procedure

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“Retreat, hell! We’re not retreating, we’re just advancing in a different direction.”

  • General Oliver P. Smith

Something that was infrequent in my playtest campaign was chases, either of the pursuit or flight variety. And that was certainly not for lack of trying, but my playtest group had a knack for alpha striking anything I threw at them and rarely being on the back foot. Part of that was that they had a good sense for information gathering and picked their engagements when they could help it.

There were certainly instances where they were in pursuit, but I tended to handwave those situations via GM adjudication and simply described the outcome based on logical inference. Not a terrible way of doing it; however, it sort of only works if the outcome isn’t in doubt, and that saps all the tension, aye?

Something I want to emphasize moving forward is that retreat is an option, and that not everything you encounter can be beaten the first time, thus I’ve thrown together a chase procedure, either for pursuit or for being pursued.

The procedure itself is not particularly crunchy, and is more trying to get the tone or “narrative” dry heave of the chase. Thus, things like distance or lead are handled in relative terms; this procedure is more a framework for GM adjudication and a way to prompt player decision and questions.

Evasion

Situations may arise where either side no longer (or never was interested) in a fight. For NPCs this is typically indicated by a morale roll, for PCs this is determined by the players. Those attempting to escape do so on their round of Initiative. On a surprise round, the unsurprised side can choose to automatically flee the encounter.

In the case of pursuit, the players may choose to chase a fleeing enemy, or the enemy may choose to chase the players. This can be indicated by a reaction roll of a low result.

The Chase

A Chase is used when one side attempts to catch another or escape pursuit over a short period of movement. Each chase round represents approximately 30 seconds to 1 minute.

The GM determines:

  • Which side is the Pursuer and which is the Pursued
  • The goal of each side
  • The starting Lead
  • The Lead required to escape
  • Any modifiers
  • The general route and obstacles

Groups may chase together. A group moves using its slowest member as the baseline speed. Any member may break off and become a separate pursuer or pursued.

Lead represents distance, position, and opportunity.

  • Lead 0: Caught
  • Lead 1–2: Close
  • Lead 3–4: Moderate distance
  • Lead 5: Far
  • Lead 6+: Escaped

Adjust these values as appropriate for the situation.

Chase Round

Each round:

  1. Both sides declare actions.

  2. Both sides roll:

    2d6 + Ability Modifier + Relevant Skill + Modifiers

  3. Compare results.

The winner gains +1 Lead.

If the Pursuer wins, reduce Lead by 1.

If the Pursued wins, increase Lead by 1.

The GM determines which ability and skill apply based on circumstances. Open sprint chases use Strength + Athletics, while a more closterphobic environment such as an urban sprawl will be Dexerity + Athletics.

Modifiers

Apply bonuses or penalties as appropriate.

Examples:

Burden

  • Carrying Something Heavy: -1
  • Heavy burden: −2
  • Difficult terrain: −1 to −3

Movement Advantage

  • Approximately twice as fast: +1
  • Approximately three times as fast: +2
  • Approximately five times as fast: +4

Flight, incorporeal movement, unusual mobility, or similar advantages may grant larger bonuses.

Attacking

During the chase either side can choose to make a single ranged attack:

  • The Attack is made at a -2 to -4 penalty including whatever other penalties that would apply based on range or circumstances.
  • The attacker loses 1 Lead

Obstacles

During a chase, the GM may introduce obstacles to reflect terrain, crowds, weather, hazards, or changing conditions.

Obstacles should alter decisions rather than stop movement entirely.

Examples:

  • Fences, walls, locked doors
  • Traffic, crowds, narrow alleys
  • Mud, unstable footing, steep terrain
  • Darkness, smoke, poor visibility
  • Construction sites, debris, difficult routes

When an obstacle appears, the GM may:

  • Change the relevant Ability or Skill for the next roll,
  • Apply bonuses or penalties
  • Prevent certain actions
  • Require a participant to split from their group
  • Offer a slower but safer route

Participants may describe how they overcome obstacles. Clever approaches, preparation, equipment, or advantageous positioning may grant bonuses or ignore penalties.

Obstacles should create choices and change the character of the chase, not replace the chase roll itself.

GMs should feel at liberty to use a variety of Ability + Skill combinatons or take player suggestion as to what should be rolled. E.g. DEX/INT + Streetwise to navigate a bustling crowd. CON + Athletics to trudge through a deep patch of mud. DEX + Lockpick to quickly force open a locked door.

Ties

If both sides roll the same result, either side may choose:

  • Halt and make one attack normally.
  • Halt and make a defensive action (e.g. dodge, take cover.)

Ending the Chase

If the Pursued reaches the required Lead, they escape.

If the Pursuer reduces Lead to 0, they catch the target.

If combat begins immediately after capture, the Pursuers gain a surprise round.

Other Types of Chases

These rules can also be applied to other circumstances besides on foot chases with some slight adjustment and adjudication.

For vehicle rules go check out my Vehicle rules article or use whatever rules you want for vehicle statistics.

During a vehicle chase, one participant acts as Driver and makes the chase roll as normal. Passengers may each choose one action per round:

  • Assist Driver: Passanger assists the driver, such as spotting incoming hazards, managing maps or GPS, or other assistive actions, on a successful skill check determined the GM the driver gets a +1 to their Chase Roll.

  • Attack: Can make a single attack that round, or lay down suppressive fire giving the enemy a -1 penality to the Chase Roll.

  • Use Ability/Item: Characters may use an ability which would plasuibly help them or hinder their enenmy, (obviously up to GM discretion)

Notes

To clarify again, this is a more loose procedure than anything else, and that’s fine, as I didn’t want to create a minigame with hardcoded outcomes, and I’m perfectly content to have things rely on GM discretion instead of enumerate all possible actions, thus I didn’t cover things like spells or abilities as those would be fairly contextual during a chase. I’m sure as I run more games and playtests I’ll come back and refine or tweak some things.