P3 thieves and barrow: crows and foxes steal food left out; the barrow with its guards, coffin loot and key pieces; blunt club vs bone (protocol 10)

docs/PROGRESSION_DESIGN.md

@@ -1,7 +1,7 @@
 # Progression and challenges design
 
-Status: **P1 (iron) and P2 (stone) built; P3 started (the alpha)**; the
-rest of P3, and P4-P5, are proposals.
+Status: **P1 (iron), P2 (stone) and P3 (adversaries) built**; P4-P5 are
+proposals.
 
 *As built in P1:*
 - Iron nuggets (70, in the scree under the rim), clay (60, on the lake
@@ -66,7 +66,34 @@ rest of P3, and P4-P5, are proposals.
 - Drops: bear hide, 2-3 fat (fire fuel, three times wood), 5-7 meat. Fur
   rug (bear hide, 2 fibre): in a sheltered room, Cozy: +4 warmth and
   Rested twice as fast. Network protocol 8.
-- Not yet: crows and foxes, the barrow and its guards.
+
+*As built in P3 (crows and foxes):*
+- Food left on the ground with nobody within 10 m for 20 s draws a thief
+  from 35 m away (at most 3 at once): a crow by day, a fox from 17:30 to
+  06:30. Food in a chest is never touched by them.
+- A crow flies in, lands and eats one every 3 s; anyone within 7 m and it
+  takes off. Shot down: 1-2 feathers.
+- A fox slinks up and runs off with the whole stack; come within 10 m
+  while it's creeping in and it bolts empty-handed. Kill it while it's
+  carrying and it drops the food; let it get 45 m from everyone and it's
+  gone. Raw meat and a hide.
+
+*As built in P3 (the barrow):*
+- One per island, on open ground (55 m+ from the spawn, 70 m+ from the
+  den; looser on lumpy islands): a grass mound you can walk over, a stone
+  passage into a 4 x 4 m chamber with a coffin, ringed by standing stones.
+- Three guards (80 HP, hit for 20, move at 3.4 m/s: slower than you walk)
+  stand at their posts. They wake when someone is inside the stone ring at
+  night or any time after day 10, when the coffin is opened, or when one
+  is hit. Fire and torches don't bother them. Beyond 22 m from the barrow
+  they give up and walk back to their posts.
+- The club is blunt: +50% on bone. Guards drop a little iron.
+- The coffin: 1-3 iron bars, 3-6 nuggets and a barrow key piece (three
+  open the standing stones, P5). It fills again 5 days after it was
+  emptied, at dawn with nobody about, and the fallen guards are back.
+  Emptied coffin and fallen guards are saved. Network protocol 10.
+- Not yet: iron scrap (bars and nuggets instead); the standing stones and
+  the Old Stag (P5).
 
 Today the island runs out of goals after a few days: once you have stone
 tools, a hut, a bow and a fire, the only threats are wolves at night, the