What Run is
Every fight in Phantasie III opens with a short menu. You can Fight, Greet the monsters, ask them to Surrender, Beg for mercy, or Run. The manual calls it Flee, and the key is R. Run is the way out of a fight you do not want. If it works the fight is over at once, with no treasure and no experience, and nobody on either side is hurt.
Normally Run has to roll the dice, and it can fail. The chance depends on the kind of monster in front and on how dangerous the two groups are together. Against the three Rangers and two Scribes in the clips, the party gets away 69% of the time. When the roll fails the game says "You don't get away...", and the monsters get a whole round of blows before you can give a single order. Against the strongest monsters, from the Dark Gnome on, a Run that has to roll never works at all. The manual warns about it in its tips. "Remember, if you flee and fail the monsters get free shots at your characters."
There is one time Run needs no roll. When the party surprises the monsters, or finds them asleep and attacks, it may run from that fight without a roll. That seems fair. Monsters that never saw you coming cannot stop you leaving.
What goes wrong
The free escape is meant for that one fight, but it does not stay there. Use it at once, running before the first round, and the game never takes it back. Walk into a dungeon, and the first fight there lets the party run without a roll, exactly as if it had surprised those monsters too. In the clips that happens in the Pendragon Town Archives, two steps from where the party ran.
It does not stop at one fight either. Running from the dungeon fight also ends that fight before its first round, so the free escape rides on into the next fight, and the one after. It lasts until the party stays in a fight for a whole round, or meets monsters on the map again.
And the game checks for the free escape before it looks at which monsters you face. So it even carries the party away from the monsters that never let anyone run, every one of them except Nikademus and Lord Wood.
Why it happens
The game keeps the free escape as a single number. Surprising the monsters, or attacking sleeping ones, sets it. The Run order looks at it first, and while it is set the party leaves without a roll.
Only two things set it back to nothing. One is the end of a round that the fight survives. The other is the next encounter on the map, which clears it before anything else happens. A party that runs before the first round ends the fight before any round has been played, so nothing clears the number. And a dungeon fight never touches it. It starts with the number exactly as the last fight left it.
What the fix changes
With the fix, every dungeon fight starts without a free escape. A party that surprises monsters, or catches them asleep, still runs from that same fight for free, and nothing else about running changes. In a dungeon fight the Run rolls as it should, and it works or fails as often as it would in any other fight.
In the fixed clip the Run fails, but that is the dice, and I set them for the film. Against those Rangers and Scribes the fixed game still lets the party get away 69% of the time.
How I found out
I ran the original code as one long play-through, on the same machine and with nothing changed in between, the way the game would play it. A party heard an Orc on the map, chose to fight, surprised it and ran at once. Then a dungeon fight began, the party ran again, and the second Run drew no dice at all. In a control run, where the first fight lasted a round, the same dungeon Run had to roll.
Then I watched it in the 1987 game itself, in an Amiga emulator, with the emulator's debugger reading that one number. A hero heard monsters outside Pendragon, the party surprised them (the game's own 30% chance came up) and ran at once. The number stayed set on the map, into the Pendragon Town Archives and at the start of the fight there, and Run worked at once. I used the debugger to make the archives give a fight on the first step, and nothing touched the number. It went back to nothing only after a round of a later fight.
About the clips
The clips are our recreation of the 1987 game, with my own party of heroes, played twice, with the fix off and then on. Both play the same until the last Run. I set the dice so that the monsters come on cue (the surprise outside Pendragon is a 30% chance, and a fight on that first step into the archives a 10% chance), and in the fixed clip so that the last Run fails. Each clip pauses on the lines you need to read.
In my recreation
My recreation plays the game exactly as it shipped in 1987 unless you ask for a fix. This one is listed as Free escape in next fight.
In 1987
A battle that ends in its first round (a surprised party that runs at once, for instance) leaves a free Run behind, so in the next dungeon battle Run works without a roll in the first round.
With the fix
Every dungeon battle starts without it.
I left it out of my fixes, so a game disk made With Justin's fixes plays it as in 1987; pick Choose my own to have it.
When you make a game disk, the game asks which rules it plays: The 1987 original, With Justin's fixes, or Choose my own. To change a disk later, pick Set fixes on disk on the list of disks.