The seige is broken, the attacking army has lost it, the defenders are being crushed, the women are lamenting, shit's on fire. You're in the invading army. There's pillaging to do, and last stands to counter. Yep, it's barbarian time.
Running a city-sacking adventure is surprisingly easy. Just pretend it's a big dungeon. The moral stickiness is a bonus. You're not getting a map from me, it wouldn't help you anyway. Use your own, mark of points of interest. Those are your "rooms". The city streets are your "hallways". Ignore the nitty-gritty, details only matter when they matter.
Every dungeoncrawl/citysackcrawl needs wandering "monsters". Have a healthy chance of encountering these, perhaps 1-in-6 for every ten minutes, or 100% whenever you walk between two points. Roll 1d12 for who you meet, and then another for what they're doing. Most of the time they won't be hostile. Many combinations will be silly, and that's a good thing. Entries with an asterix (*) are doing the opposite of the "doing" roll.
| D12 | "Monster" | Doing |
|---|---|---|
| 1 | Woman with D4 Children | Hiding treasure |
| 2 | D6 Militiamen | Ready to fight |
| 3 | 2D6 fellow citysackers* | Hiding |
| 4 | D6 Nuns | Praying |
| 5 | D6 Clerics | In hysterics |
| 6 | 1D12 Civil Servants | Trying to put out a fire |
| 7 | D4 Philosophers | Rolling a bathtub around in circles |
| 8 | D6 Goblins | Reciting apocalyptic passages |
| 9 | D6 Criminals | Swearing loyalty to the invaders |
| 10 | 1 Barbarian* | Going about their day |
| 11 | D3 Musicians | Franically recording what they see |
| 12 | 1 Scholar | Begging you to spare a holy site |