In my experience, it tends to be all or nothing. Few times will the party leave a downed party member behind, and retrieving a downed party member contributes to the death spiral they're already dealing with. So retreat tends to be all or nothing, and usually at the start of an encounter when the character all have a chance of getting away sucessfully.
So, how do you handle retreat? Do you?
Thinking about this question I realised that retreats of various kinds happen very often in my games, both the ones I run and also the ones in which I am a player. This is not surprising.
Retreating is an absolute staple of adventure of all kinds, pulp fiction, fantasy and scifi. Be it Han Solo fleeing from Strom Troopers in the Death Star or the Fellowship of the Ring fleeing through Moria from the Balrog. I would suggest then that as a GM if you aren’t consciously incorporating them into your game you are perhaps missing a trick.
In gaming terms, I would say there are two main flavours of retreat. These are the Rout and the Escape.
The Rout occurs when the players ideally don’t want to leave combat but due to circumstances, (generally losing) one or more of them realises they need to leave or they are going to die.
The Escape occurs when the players may or may not have completed their goal but fleeing is obviously the new priority and there is no question amongst the (sane) members of the group. For example, fleeing a lava flow or a cave in.
Of course, the Rout and the Escape can occur at the same time (a Player’s action removes a supporting wall in a castle for example).
The RoutHandling the Rout depends heavily on the type of game you are running and the player characters involved. For example, if the group is prepared for a TPK or at least some party deaths. Some players may feel the need to hold off pursing enemies and go down fighting.
With regard to fleeing it is worth noting that in some systems the movement rules are different if a character is literally just sprinting away heedless of their surroundings compared to moving tactically in a normal combat round.
It is also worth considering what any enemies are doing. Are they happy to have driven off the intruders and in fact aren’t pursuing? Were they expecting a pursuit and have plans in place for the eventuality (perhaps dropping portcullis or sounding alarm bells)?
What happens if the players are caught? Most enemies will simply continue to attack but in other scenarios there may be a different outcome. City Watch may seek to arrest criminal players for example. If the enemies are not pursuing what are they doing? Looting or eating the bodies of fallen heroes, summoning reinforcements? Shoring up their defences for a counter attack? In my experience the reaction of the enemies is the main determining factor in whether a TPK will result.
In any case once combat completely degenerates into fleeing I believe the Rout is best determined in an abstract narrative way rather than strictly adhereing to the mechanics of movement. Rather than a static movement value to determine success use Stats and skills like Athletics, Dexterity or Talents like Fleet Footed and Swift Stride. Differences in movement can be used to grant bonuses to rolls. Inaddition to emphasise the variety of skill sets being used as well I add in obstacles. These can be as simple as tripping over tree roots to jumping past closing doors. Failing a roll doesn’t necessarily mean the player is caught but it might mean a penalty to a next roll or taking some damage from an opponent on their heels.
For a group of four or five players I would suggest between 5-11 obstacles split between the party some of which may overlap but they shouldn’t all be the same. Also don’t be afraid of having the fastest (or first) to leave essentially be able to avoid any obstacles and get clear without any rolls. This can demonstrate the obvious advantage of cowardice!
Finally, as a GM it is worth having an end point for the Rout. At what point are the players safe. You don’t need to explicitly tell the players this and indeed within reason concealing this can lead to some amusing (and perhaps realistic) outcomes with the players fleeing far further and farther than necessary.
The EscapeThe Escape is mechanically rather similar to the Rout with the exception that for narrative reasons the danger not fleeing presents is often obviously grave and hence needs to be handled with care.
For example in a Rout having been beaten by a tribe of orcs a party flees. If one of their number is caught and as a GM you are being merciful it is easy enough to simply say the party member is captured and dragged back to the orc warlord for interrogation. By comparison in an Escape the group is more likely facing something along the lines of an avalanche or lava flow which cannot be easily survived without breaking the verisimilitude of the game. In this case I would suggest making it clear to the players that the main danger will kill them but mechanically make it quite easy to avoid if they keep moving. However, the obstacles the players face are of a collateral nature linked to the main threat.
For example, recently my group fled a cave being used by the vile ratmen for foul ceremonies to their dark god. The cave was closing in around them, its sealing induced by a spell from the Skaven Grey Seer. The players fled. I determined it was unlikely the players would be sealed in if they kept moving but they did have to contend with a barrage of falling stones and some took damage on the way out. In addition, saving their NPC comrades was less certain.
Similar to the Rout as a GM have a clear point where the players are safe. Unlike the Rout it is generally more dramatic when the players can see safety in sight and can heroically make a final push for it.
Something to consider is that some scenarios naturally lend themselves to Retreating. These are all scenarios I have run that I knew ahead of time would have a Retreat involved.
Warhammer 40K - Deathwatch: Space Marines planting a nuke on a derelict space station full of alien monstrosities.
Warhammer 40K – Dark Heresy: The Acolyte cell fleeing from cultists who had attacked the hotel during the mission briefing!
WFRP: Fleeing a Skaven temple that was caving in (as noted above).
WFRP – The Empire in Flames: Fleeing a Chaos portal that has just opened
Pendragon – Once and Future King: Players are Varangian Guards fleeing from a castle after having robbed the Imperial treasury as the demonic spirit of the Euphrates is unleashed and Saracens attack (it makes more sense in context).
Pendragon – Once and Future King: Calmly retreating in good order after negotiating with some Welsh raiders, both sides having taken casualties (this one is border line a RP solution rather than full retreating but there was a lot of anxiety over a double cross that the players wanted to leave quickly).
Legend of the Five Rings: Fleeing with an Imperial child from a far superior evil monk that is planning to kill said Imperial child.
Numenera: Fleeing from Sathosh raiders, through a fortress experiencing both a spatial and temporal collapse and into a time portal…
Finally, my all time favourite (unplanned) retreat happened in a Dark Heresy game when a player character picked a fight with a group of wasteland savages. The rest of the group backed him and squared up to the wastelanders. First round of combat the player character who had initiated the fight fled. The character proceeded to run a large arc around the border of the combat area. When it was clear the fight had been won the player character returned and finished off the leader of the wasteland savages. Needless to say, as GM I found this amusing. The PCs own group less so.