P1 iron: nuggets, ore, clay, kiln, smelter, forge, iron tools and arrows, lantern, tool wear and repair

docs/PROGRESSION_DESIGN.md

@@ -1,6 +1,24 @@
 # Progression and challenges design
 
-Status: **proposal**. Nothing here is built yet.
+Status: **P1 (iron) built**; P2-P5 are proposals.
+
+*As built in P1:*
+- Iron nuggets (70, in the scree under the rim), clay (60, on the lake
+  shore) and rusty boulders (about a quarter of the boulders, mostly near
+  the rim; iron ore when mined) are on every island, old worlds included.
+- Charcoal kiln (2 wood -> 1 charcoal, 20 s), smelter (1 ore or 3 nuggets +
+  1 charcoal -> 1 bar, 30 s) and forge. Kiln and smelter open like chests
+  and work on their own (also through a slept night and on a server).
+- At the forge: iron axe and pickaxe (twice as fast), iron spear, iron
+  arrows (x1.5 damage, the bow uses them first), nails, lantern.
+- **Durability** (decided: yes): stone tools 60 uses, club 80, wooden spear
+  50, bow 100, rod 80, iron tools 200 (iron spear 180). A bar on the slot;
+  a warning near the end; it breaks at 0. Repair in the crafting panel's
+  Repair tab: stone and wood at a workbench (a flint, wood or fibre), iron
+  at the forge (an iron bar). Wear stays with the item in chests, graves,
+  on the ground (a thrown spear) and in saves.
+- Not yet: the cooking pot and stews, the iron-banded door (with P3, when
+  something can break doors), iron armour.
 
 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