There are a lot of small modifications to the rules to fit this gritty setting. There's a new "recover from duck back" reaction that may send grunts running for their lives. With an optional rule, figures may become out of ammo for the rest of the battle. Items, which seemed plentiful to me in 5150 New Beginnings, become very precious in an ATH campaign as your group needs food, fuel and medical supplies to survive.
In this game I went with a one-shot Wandering encounter. I created a lone wolf star called Tom (rep 5, fitness 5, people 3, savvy 4.) I got a 6 when rolling for the first attribute so I got one extra: friendly and white knight. To those, I added steely eyes. Tom's attributes made me think that his companion should be of the sheep class, so I rolled Shelly (teen female, rep 2, fitness 1, people 2, savvy 0, sure handed.) Tom carries an SMG, knife and a pair of binoculars, while Shelly has a pistol and a knife. Each of them has two units of food and one unit of medical supplies. So here I was with the typical post-apocalyptic duo of tough guy and the young girl he rescued from raiders and is teaching how to survive.
I decided that the place they are passing through has an Encounter Rating of 1 (middle of nowhere,) rolled evening for the part of day (thus reducing visibility,) and rolled for lack of sleep getting no ill effects. For the board, instead of randomly rolling terrain I simply scattered some green patches marking areas of tall grass, bushes and trees that block line of sight and otherwise work like woods in the rules.
After placing my characters on sector 8, I rolled for the PEFs getting a rep 4 PEF on sector 1, a rep 5 PEF on sector 3 and a rep 3 PEF on sector 5. Here's the setup at the beginning of the game (I'm using small bug miniatures as PEF markers.)
Here's the battle report, with some narrative interpretation (and game commentary in square brackets):
Tom couldn't stop thinking this was a mistake. Crossing the wasteland in the dark, with some farmer girl that had never left her settlement -- until she was taken by raiders, that is. Still, they had to keep moving because the surviving raiders would come hunting for them with the sunrise.
This part of the wasteland had several patches of vegetation. The plan was to move around them, close enough to use them as cover but never stepping inside, to avoid stirring whatever might be in there. As they approached the first patch of tall grass, Tom motioned Shelly to wait. Carefully, he stepped ahead with his submachine gun ready. A large rat scurried across the dry ground and disappeared in a bush. "It's nothing, let's keep moving," he whispered to the teenager.
[On the third turn, Tom moved to a position with sight to and within 12" of a PEF (remember it's evening) but it proved to be nothing but nerves, so the group simply completed their movement.]
They slowly moved between two patches of bushes and tall grass, always pausing to hear any noises and movement around. Evening was turning into night and all was terrifyingly quiet.
[On the next turn they moved towards the center of the map, getting in range of another PEF -- again, nothing but nerves.]
Minutes later, Tom caught a glimpse of metal straight ahead. Pulling the girl to his back, he leveled the SMG and kept walking. A seemingly young man, with a mess of hair and beard, emerged from the darkness, pointing a small gun (maybe a machine pistol?) at them. The three people kept walking until they were only a few yards apart. "We're just passing through," whispered Tom, noticing that the man was looking curiously at Shelly. Long minutes passed but eventually both men lowered their guns and the stranger walked away, into one of the patches of tall grass. Tom kept standing there for some time more, until there was no more noise coming from the grass.
[On the fifth turn Tom's group activated first and moved in range of the third PEF. This time the PEF resolved as a neutral lone wolf. Tom failed on his people challenge, so the NPC became unfriendly. On the next turn, he walked into the nearby woods.]
Tom pulled Shelly's arm, signaling that they should start moving again. As they were about to turn and move away, he heard the sound of the grass leaves giving way to someone passing through, and a metallic "click." The young man had returned and, wild-eyed, raised his weapon to aim at Tom's head.
[Now here's the amazing part: on the following turn the NPC activated first and rolled an action of "move towards nearest player." This would bring him back in sight of my characters -- and an unfriendly NPC becomes an enemy in future meetings... so the lone wolf walked back to the edge of the woods and triggered an In Sight test!]
Tom crouched and fired a burst from his SMG. The young man let out a short scream and fell to his side, while letting a wild burst of machine pistol fire. Nearly at the same time, two pistol shots sounded to his left: Shelly had pulled her gun and fired at the stranger.
[Tom got two successes, enabling him to act first. He fired his SMG getting two hits and taking the lone wolf NPC out of the fight. Shelly also got one hit but that didn't make much difference.]
Tom didn't bother to check if the stranger was alive. The world was a harsh place, and it was good enough that he didn't finish him off or rob his things. Besides, all the sound and flare from gun fire was bad enough, and he didn't know how Shelly would react when she started thinking about the firefight. So he just put an arm around her back and pulled her along, moving quickly into the night.
[After the battle, my group simply had to walk to the edge of the map to complete the encounter, since there were no more PEFs to be resolved.]
There's a lot to like in After the Horsemen. The game moves fast (I love the sector-based movement of PEFs, also featured in 5150 New Beginnings) and keeps you on your toes. A full survival campaign is now on my "game projects" list. For now, I might try a few more games with Tom and Shelly.