Fleeing and Pursuit Through the Eras of D&D

Original D&D (c. 1974)

The very first D&D book doesn't even mention movement, much less pursuit. As a supplement to Chainmail, it assumed those movement rules could be used. In Chainmail, however, you controlled units of troops, not single heroes, so each round consisted of moving units, then missile fire, then artillery fire, then melee exchanges; at this point, fleeing a battle simply means moving away from other units. Some morale checks could force your troops to retreat (or be routed), which could get you 1 1/2 moves away, though with your backs to the enemy (a flanking bonus) and no ability to counter or move again until they spent a turn rallying.

It's not until the 1974 "Blue Book" edition that rules for fleeing are even mentioned:

If combat is broken off, the fleeing party must accept an attack without any return on his part, the attacker adding +2 to his die roll for hit probability, and the armor class of the fleeing party can not include a shield.

Further details are left to the DM; presumably turn-by-turn movement resumes, with the enemies opting to give chase either at the DM's whim or with an occasional spot rule:

If the party decides to flee they may be able to delay pursuit by discarding some of their possessions. Unintelligent montsers will stop to pick up food half the time (roll 1-3 on a 6-sided die) and intelligent monsters will stop for treasure half the time (roll 1-3).

Additionally, in the section on Time and Movement in the Dungeons (pg 9):

Faster speeds can be allowed for charging or a short sprint. If a character is being pursuid, however, he may have to throw away heavy treasure or armor in order to escape.

In this era, the speed of monsters was generally comparable to that of PCs; PCs (and humanoid NPCs) move 240 feet when unarmored, 120 feet in armor, and half if carrying a heavy load (e.g. treasure). Humanoid monsters followed those rules, with smaller monsters like goblins significantly slower than all but the slowest PC. Some monsters, though, would be nigh impossible to escape as a typical adventuring party, forcing dire choices like abandoning slower members or fleeing ahead of the party to improve your own odds. Wizards would be particularly good at this, as would the henchmen, hirelings and retainers likely accompanying you. Some of the particularly frighteningly difficult-to-escape monsters:

These are all essentially impossible for a party of adventurers to escape over open terrain, such as a long, open, wide tunnel, leaving only situational escape options (get to the door and close it before getting overrun) or "run faster than the next guy" escape techniques. There's no "rules as written" mechanisms for adjudicating these, but round-by-round combat might work well enough.

Several monsters are quite a bit slower than PCs; oozes, molds and some insects are either immobile or quite slow. This leaves the majority of monsters situationally faster or slower than the party; if an ogre (90') attacks the party while it is loaded down with treasure (60'), it may very well come down to ditching treasure.

Curiously, zombies (120') are significantly faster than skeletons (60') and thus harder to run away from. Odd.

Basic (1977 - 1983+)

Starting with the first Basic edition (sometimes called Moldvay Basic or B/X), movement speeds vary by situation. Encumbrance rules become more complex, as well. Within combat, PCs will move between 40'/round (unarmored) and 10'/round (metal armor and/or heavily burdened). Running speeds are also given, as 3 times normal combat movement. Evasion and pursuit are far more detailed:

EVASION: Sometimes one side wishes to evade (avoid) an encounter. If the evading side has a faster movement rate than the other and combat has not yet begun, evasion is automatic as long as the evading side is not forced to stop.

PURSUIT: If either side wants to pursue the other, time is counted in rounds, and both sides are RUNNING. Monsters will chase evading characters only as long as the characters are in sight.

Dropping things to distract pursuers also carries over from the blue book.

Once combat has started, a FIGHTING WITHDRAWAL (1/2 normal movement) or full RETREAT (above 1/2 normal movement) are the main ways to flee, and must be declared before each combat round.

RETREAT: Any movement backwards at more than 1/2 the normal movement rate is a retreat. If a creature tries to retreat, the opponent may add +2 to all "to hit" rolls, and the defender is not allowed to make a return attack. In addition to the bonus on "to hit" rolls, the attacks are further adjusted by using the defender's Armor Class without a shield.

While it isn't said explicitly, the retreat option seems to be one you can use at your running speed. It also appears that if your side wins initiative, it is possible that your retreat results in no attacks by the enemy. If your side doesn't win initialive, however, you've already declared you are retreating, so the extra risks above apply.

Monsters are listed with combat movement speeds, and as with the blue edition, most are between the speed of an unencumbered party and a heavily encumbered party. The same extra-fast monsters produce inescapable encounters (outside of situational options), along with a couple new ones.

The Expert book (the X of B/X) adds rules about pursuit in the wilderness, providing a table of random evasion chance, in which a smaller party trying to evade a larger party has increasingly good base chances, and some extra rules about the order of events:

Pursuit: If the party fails to evade, they must fight or move away in a random direction (no mapping). If the other group is faster, there is a 50% chance the party will be caught. If the party is not caught, they may try to evade again. Repeat the procedure until the party evades or is caught.

Rules Cyclopedia mostly restated these rules (sometimes at great lengths) but does add a couple wrinkles that could significantly change the flow of combat:

• The Evasion table is formalized to apply to all encounters, not just wilderness encounters.

• Initiative is determined every round during pursuit, with each side moving accordingly. This could result in one side moving twice in a row, if they lost initiative one round and won the next.

• Monsters make a morale check every five rounds of the pursuit or give up.

• Fighting Withdrawal is changed significantly; now it isn't really a means of escape, just an opportunity to move the fight around at 5' per round or offer a truce.

• Retreat has been rephrased to make it clear that you can't use your running speed unless you start a movement phase without being in hand-to-hand combat; the retreat maneuver uses your encounter speed instead. On the other hand, the order of events has changed a bit:

  Any enemy attacking him later in the combat round (that is, either an enemy who followed him during the enemies' movement phase or an enemy attacking with a ranged weapon) receives a + 2 attack roll bonus this round.

AD&D First Edition (1979)

Initially, First Edition had very little to say on the subject of fleeing an encounter. The Player's Handbook notes:

If the party is fleeing, all movement -- excluding encumbered movement, is 10 times faster, so each move takes only 1/10 of a turn, or 1 round.

This seems important, but that 10x faster is just the combat movement speed; anybody moving in combat does so at 10x the speed they normally do. Later, in the Melee Combat section:

fleeing means as rapid a withdrawal from combat as possible; while it exposes the character to rear attack at the time, subsequent attacks can only be made if the opponent is able to follow the fleeing character at equal or greater speed.

The Dungeon Master's Guide explains avoiding encounters in some detail (pg 63), but then leaves much of it up to the DM:

It is always possible to flee from an undesired confrontation if the other party is surprised. It is never possible to flee from an encounter where the opponent party is in strinking range. A party can always flee an encounter if it gains the first initiative.

It then lists some factors the DM should consider in determining whether evasion is successful, such as monster motivations, relative speeds, deterrents, etc, and gives a flat 50% chance of successful evasion in all other cases. Later, in "PURSUIT AND EVASION OF PURSUIT" it lists a different set of criteria for whether pursuit happens, and whether evasion is successful is detailed in a rather complex table. If the pursuers are slower than the pursued, evasion happens at 100' of distance, or 50' of distance if line-of-sight was broken, or after 5 rounds if the pursuer is not gaining. If they're the same speed, it's 150' of distance, or 80' with broken line-of-sight, or 1 turn. And if the pursuer is faster, 200' and out of sight, or the pursuer is exhausted.

How a party is supposed to get more than 200' away from a monster that is faster than them is left as an exercise for the player, but an entire page of modifiers is suggested, from distracting monsters with food or treasure, placing barriers, taking a forking path out of sight of the pursuer, etc, but this mostly boils down to DM's judgement and though it isn't stated outright it seems Gygax expects groups to continue round-by-round actions until the chase is over.

In the combat section, the rules for fleeing after combat has started is explained much more simply:

Breaking Off From Melee: At such time as any creature decides, it can break off the engagement and flee the melee. To do so, however, allows the opponent a free attack or attack routine. This attack is calculated as if it were a rear attack upon a stunned opponent. When this attack is completed, the retiring/fleeing party may move away at full movement rate, and unless the opponent purseus and is able to move at a higher rate of speed, the melee is ended and the situation becomes one of encounter avoidance.

So running away gets you one or more free atacks (at +6 and with no shield of Dex modifier to AC), and if the monster is faster than you and chasing you, it gets to keep attacking.

While it seems like Gygax wanted to facilitate dramatic chases through dungeons, the rules-as-written don't seem to support it. If you're faster than the monster you're running away from, in the best case (surprise or first initiative) you can just run away, and at the worst your front ranks suffer some attacks. But if you're slower? Not only is it nearly impossible to achieve the distances and conditions needed to end pursuit, those conditions are even harder than normal. Worse yet, if combat has already started, the monster can simply continue following and attacking.

Given this, which monsters are a dire, save yourself, drop-everything-and-run encounter? Most PCs will be moving between 120' and 60' per combat round, determined mainly by armor, with most fighting classes around 90'. Most humanoid monsters will be comparable, but numerous beasts exceed 120', and most flying monsters move at 180' or more. Notable new hazardous encounters:

For the vast majority of encounters, armored PCs are simply going to be unable to flee from a combat once it has started, so long as the monster wants to pursue. For many, many more, even unarmored PCs will be easy to run down. I don't think Gygax meant for these rules to be used, but for rulings to override them almost all of the time.

At least Gygax fixed the Zombies vs Skeletons problem. Skeletons now move 12", while Zombies move 6".

AD&D Second Edition (1989)

Much of Second Edition works the same, at least for a single PC trying to flee a combat:

• A withdrawal is up to 1/3rd of a PC's normal movement rate, not 5'.
• A situation that likely caused an ad hoc ruling is codified: if a front rank fighter withdraws, the rest of the rank can block the opponent from following.
• The free attacks a monster gets on a fleeing PC are clarified to be instantaneous and not count against their other attacks.
• Once a PC has fled, the monster can give chase on its next turn. Another rule allows characters to attack only if they've moved no more than half their movement, though charging triples that distance with some additional risks, making it simple for most monsters to continue closing with and attacking a fleeing party.

However, rather than trying to rework the hodge podge of First Edition's pursuit and evasion rules, Second Edition simply omits them (aside from a rather extensive rule set for Aerial Combat). There are no rules to adjudicate what happens when one party immediately tries to flee when an encounter is sighted, apart from a brief discussion in the Player's Handbook:

Your character's success at evading capture will depend on movement rates, determination of pursuit, terrain, and just a little luck.

Even less helpful than Gygax.

D&D Third Edition (2002)

Third Edition was the first to codify combat actions to such a degree that the ability to flee was simply an emergent property of the round-by-round rules. At the same time, the need to flee from a random or unbalanced encounter has never been lower. Outside of tactical errors, most parties can assume that it is safe to start any fight, and only consider fleeing if it starts to go wrong.

Movement

Each character has a speed measured in feet. You can move that distance as well as attack or cast a 1-action spell, and you can move before or after attacking or casting.

You can also make a double move, which lets you move double your speed, or a run, which lets you move quadruple your speed.

Similarly, the risks for fleeing from an ongoing combat are made explicit by the Attacks of Opportunity rules:

When you move in or away from an area that an enemy threatens, you provoke an attack of opportunity from that enemy.

Player characters can also avoid the penalties of running from combat by performing a Withdrawal action, essentially allowing a safer double move:

Withdrawing from melee combat is a full-round action. When you withdraw, you can move up to double your speed. [...] visible enemies do not get attacks of opportunity against you when you move [out of your starting square].

An opponent could then charge on their next turn, granting them double movement speed (in a straight line) plus an attack, so withdrawing is often only capable of allowing a full party to flee if the situation permits.

The Dungeon Master's Guide spells out the general process of adjudicating pursuit:

Evasion and Pursuit

In round-by-round movement, simply counting off squares, it's impossible for a slow character to get away from a determined fast character without some sort of mitigating circumstances. Likewise, it's no problem for a fast character to get away from a slower one.

When the speeds of the two concerned characters are equal, there's a simple way to resolve a chase: [...] have them make opposed Dexterity checks to see who is the faster over those rounds.

In the case of a long chase, an opposed Constitution check made by all parties determines which can keep pace the longest.

The Dungeon Master's Guide II offers some details for those mitigating circumstances, to make a chase encounter more interesting, but the round-by-round procedure doesn't change.

As for the movement speeds of characters, they could range from 15' (for short folk in armor) to 40' (for unarmored characters with certain class advantages, like the Barbarian's fast movement.) Most low-level monsters are within that range, especially humanoids, though top speeds for other monster types tend to grow a bit with hit dice. Those speeds are expected to be balanced for level-appropriate parties having additional mechanisms for fleeing, such as teleportation or haste.

D&D Fourth Edition (2008)

Apart from returning to movement rates measured in miniature scale (given in squares), much hasn't changed from Third. Fleeing from melee usually results in Opportunity Attacks, and rarely puts you far enough away to avoid enemies charging and attacking the following turn.

A new Move Action, Run, was added, allowing for faster movement while still leaving a Standard Action available, with some additional risks. Taking the Run move action grants you an extra 2 squares of movement (compared to a PC's normal movement of 5-7 squares), at a cost of -5 to attack rolls, provoking Opportunity Attacks, and granting Combat Advantage to enemies.

Additionally, running away from an encounter could be made into a Skill Challenge, such as the Urban Chase example given in the Dungeon Master's Guide. This is entirely optional, but gives players a menu of applicable skills (Acrobatics, Athletics, Perception, Streewise) to roll to collect enough successes to resolve the encounter. This is, notably, the first time skills are used directly in resolving a chase scene abstractly. Curiously, this approach does not make any use of the various creatures' movement speeds. There's also not much guidance given for when or how to switch to this system when PCs opt to flee an ongoing combat.

Similar to Third edition, lower-level monsters tend to be slower than or similar speed to PCs, and this scales up with level as PCs also gain more movement powers. Unlike Third edition, nearly every class will gain access to such abilities, due to the Powers system shared by every character.

D&D Fifth Edition (2014)

Much of Fifth Edition's movement rules are a restatement of Third Editions. For example, instead of the "Combat Withdrawal" maneuver allowing slow retreats without free attacks against you, Fifth Edition has the Disengage action. This is treated the same as an action ("standard action" in Third), which means you can move your normal encounter speed safely.

Similarly, the "double move" action has been replaced by the "dash" action, which converts an action into an additional movement but otherwise behaves nearly the same. However, many classes gain the ability to perform a Dash using their once-per-round Bonus Action at relatively low levels, such as the Monk's Step of the Wind or the Rogue's Cunning Action, resulting in some characters being able to safely Disengage and move double their speed in the same round.

Pursuit and evasion are detailed in more depth in the Dungeon Master's Guide:

Chases

Strict application of the movement rules can turn a potentially exciting chase into a dull, predictable affair. Faster creatures always catch up to slower ones, while creatures with the same speed never close the distance between each other. This set of rules can make chases more exciting by introducing random elements.

The round-by-round resolution process is mostly unchanged, with each participant having an action and a move on each turn, resulting in a running combat. Some additional optional rules are suggested, such as controlling the number of times a Dash action can be used with a Constitution check, preventing Opportunity Attacks between participants, and providing a Stealth mechanic to escape a chase by hiding.

The Dungeon Master's Guide also suggests adding Chase Complications to Urban or Wilderness chases, listing a bunch of mini-challenges in a random table that can drastically change the progression of a chase, such as having to treat a crowd as difficult terrain, or being blinded by blowing dust, both avoidable with a skill check.

Summary

Early editions of the game emphasized the need for players to pick and choose fights and flee from ones they cannot win, and there was no expectation that encounters would be balanced. At the same time, there were no detailed systems for handling fleeing combat or escaping pursuers, leaving this aspect of the game up to spot rulings and house rules. Later editions provided more systems and options for escaping combat, while simultaneously reducing the need by adding an expectation of balance to the majority of encounters.