diff --git a/Artifact-List.md b/Artifact-List.md
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+++ b/Artifact-List.md
@@ -57,6 +57,7 @@ This does not allow you to see underground.
 Your size and height are tripled.  You gain temporary hit
 points equal to your max hit points.  Your damage with
 strength based attacks is doubled.  Your movement speed
-is doubled.
+is doubled.  Temporary hit points return after 1 minute of
+no combat.
 
 
diff --git a/Artifacts-Game-Arena.md b/Artifacts-Game-Arena.md
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+# Artifacts Game Arena
+
+The arena is divided into geographic regions, each with a
+simple puzzle that reveals an artifact or vault.
+
+## The Lake
+
+A lake about 500ft across. In the center is a small island
+(20ft diameter) with a sandy beach, a palm tree, and two
+lounge chairs. If two people sit in the chairs
+simultaneously, a vault rises from the sand.
+
+## The Frozen Pond and Cave
+
+A shallow frozen pond surrounded by dead trees. A glowing
+object is visible under the ice. Breaking the ice reveals a
+magical light. Adjacent to the pond is a cave filled with
+magical darkness that can't be dispelled. The light from the
+pond cuts through it. At the back of the cave system is an
+artifact.
+
+## The Bell Tower
+
+A crumbling stone tower with a bell at the top. Ringing the
+bell causes a compartment to open, revealing an artifact.
+Once rung, the bell keeps ringing loudly for 3 minutes.
+
+## The Hedge Maze
+
+A small hedge maze, maybe 100ft across. Not difficult to
+solve. The center contains a stone crypt with a small plate
+beneath the doorknob showing a fingerprint. Scattered
+throughout the maze are statue body parts. The statue's
+hands have matching fingerprints, but the fingers are curled
+inward. Assemble the statue and it animates, places its
+finger on the plate, and opens the door, revealing an
+artifact.
+
+## The Hot Springs
+
+A series of steaming pools, 20ft deep, crystal clear.  The
+water is warm and pleasant.   At the bottom of the pools are
+tunnels connected to a central chamber.  The tunnels are
+quite long: getting there and back without water breathing
+is not feasible.  The chamber has an artifact on a raised
+dais.
+
+## The Windmill
+
+On top of a large hill, an old windmill.  To get it turning
+again, you'll first need to unjam the gears, which contain a
+large wrench.  Then, you'll need to check the millstones,
+which have been glued together with some sort of strong
+adhesive - acid will dissolve it.  Once you do both these
+things, the mill is free to turn.  Any wind magic works. You
+can also do it by brute force: make a STR check DC25. Up to
+three people can shove at the same time: if they do, make up
+to three DC25 checks, and if any of them succeed, the
+windmill turns.  When it turns, a mechanism reveals an
+artifact.
+
+## The Campfire
+
+A clearing with an unlit campfire, pre-stacked with wood.
+Get it roaring hot, which takes about 5 minutes without magic
+(you can do it a lot faster with a fireball), and a vault
+will rise up in the center of the fire.  Putting an artifact
+into the vault without taking damage requires ingenuity or
+fire resistance.
+
+## The Orchard
+
+A grove of fruit trees. One tree is much larger than the
+rest, with an artifact lodged high in its branches (about
+40ft up). The trunk is smooth and branchless for the first
+20ft — climbing requires a DC 15 Athletics check or creative
+problem-solving.
+
+
+## The Graveyard
+
+Inside a wooded area full of dead trees and mist,
+a small graveyard with six headstones and a mausoleum. On
+the mausoleum door are the words, "Rest in Peace my Lady,
+Lover of Poetry." Each headstone bears one line of a poem.
+The lines are in random order. Reciting the poem in the
+correct order at the door opens the mausoleum, revealing a
+vault inside.
+
+In clockwise order around the mausoleum:
+
+* And all the roses withered where she lay
+* A lady fair who loved the morning sun
+* That she may hear the poetry once more
+* But shadows crept and stole her from the day
+* Recite this verse and open wide this door
+* Would dance among the roses, every one
+
+The correct order is:
+
+1. A lady fair who loved the morning sun
+2. Would dance among the roses, every one
+3. But shadows crept and stole her from the day
+4. And all the roses withered where she lay
+5. Recite this verse and open wide this door
+6. That she may hear the poetry once more
+
+## The Statue Garden
+
+Deep inside a field of large boulders, an array of lifelike
+stone statues frozen mid-dance. Play music and they come
+alive and dance in pairs — but one statue has no partner.
+Dance with the partnerless statue: Performance check DC 20.
+Get the steps right and your feet press a series of buttons
+on the ground, causing a pedestal to rise with an artifact.
+
+## The Underground Lake
+
+A cavern filled with water.  Swimming in the water are all
+manner of aggressive fish.  The ceiling and walls are
+dripping with water and algae and is quite slimy, even
+"spider climb" won't make you stick.  On the far bank are a
+bunch of aggressive crabs.  Beyond the crabs is a short
+passage leading to a dais with an artifact.  The PCs will
+have to decide whether to cross in the water (requires
+dealing with the fish), or crossing by some other means
+which may avoid the fish, and whether to send the whole
+party or just part of it.
+
+> Swarm of Razor Fish (3 swarms in the lake)
+>
+> AC 13. HP 28 (8d8-8). Speed 0 ft, swim 40 ft.\
+> STR 10 (+0), DEX 16 (+3), CON 9 (-1), INT 1 (-5), WIS 7 (-2), CHA 1 (-5).\
+> Saving Throws Str +0, Dex +3, Con -1, Int -5, Wis -2, Cha -5
+>
+> Swarm: can occupy another creature's space. Resistance to bludgeoning, piercing, slashing. Immune to charmed, frightened, grappled, paralyzed, petrified, prone, restrained, stunned.\
+> Blood Frenzy: advantage on melee attacks against any creature that doesn't have all its HP.\
+> Water Breathing: can only breathe underwater.
+>
+> Biting Swarm: +5 to hit, reach 0 ft (creatures in swarm's space), 2d6 piercing (or 1d6 if swarm is below half HP).
+
+> Giant Crab (6 crabs on the far bank)
+>
+> AC 15 (natural armor). HP 19 (3d8+6). Speed 30 ft, swim 30 ft.\
+> STR 14 (+2), DEX 12 (+1), CON 14 (+2), INT 1 (-5), WIS 9 (-1), CHA 3 (-4).\
+> Saving Throws Str +2, Dex +1, Con +2, Int -5, Wis -1, Cha -4\
+> Skills: Stealth +3.
+>
+> Amphibious: can breathe air and water.
+>
+> Multiattack (2 claw attacks):\
+> Claw +4 to hit, reach 5 ft, 1d6+2 bludgeoning and target is grappled (escape DC 12).
+
+## The Crystal Chamber
+
+A cavern studded with glowing crystals. In the center, an
+artifact is suspended inside a large formation that looks
+like crystal but close inspection reveals to be thick glass.
+It's impervious to weapons. A handle on the wall releases a
+flood of ice-cold water directly onto the glass. Heat the
+glass (fire magic, torches, etc.) then hit it with the cold
+water — the thermal shock cracks it. A few cycles and it
+shatters, releasing the artifact.
+
+## The Chasm
+
+A deep underground chasm, 40ft across and 200ft deep.
+Hanging from the ceiling are rusted chains. Swing across on
+one — each swing requires a DEX check DC 12 to grab the next
+chain (failure leaves you dangling), and each chain breaks
+on a roll of 1 on a d6. It takes 3 chains to cross. If a
+chain breaks, more chains are draped across the chasm at
+various depths — DEX save DC 15 to catch one on the way
+down. Take 2d6 bludgeoning from the impact. Then you have to
+figure out how to get back up. On the far side is a huge
+lever. The whole party must climb onto it — it takes their
+combined weight to depress it, causing a compartment in the
+wall to open, revealing an artifact.
+
+# Empty Biomes
+
+## The Meadow (above ground)
+
+A wide open grassy field with wildflowers. Good visibility in all directions — you can see other teams coming. A herd of elk graze here. They're not hostile unless provoked.
+
+> Elk (6 in the herd)
+>
+> AC 10. HP 13 (2d10+2). Speed 50 ft.\
+> STR 16 (+3), DEX 10 (+0), CON 12 (+1), INT 2 (-4), WIS 10 (+0), CHA 6 (-2).\
+> Saving Throws Str +3, Dex +0, Con +1, Int -4, Wis +0, Cha -2
+>
+> Charge: after moving 20 ft straight, first melee hit deals +2d6 damage.\
+> Ram +5 to hit, reach 5 ft, 1d6+3 bludgeoning.\
+> Hooves +5 to hit, reach 5 ft, 2d4+3 bludgeoning.
+
+## The Ruins (above ground)
+
+Crumbling stone walls and collapsed buildings. Good for hiding and ambushes. A few giant rats nest in the rubble. Among the ruins, crude stairs lead down to the Bone Pit — the entrance to the underground areas.
+
+> Giant Rat (4 in the ruins)
+>
+> AC 12. HP 7 (2d6). Speed 30 ft.\
+> STR 7 (-2), DEX 15 (+2), CON 11 (+0), INT 2 (-4), WIS 10 (+0), CHA 4 (-3).\
+> Saving Throws Str -2, Dex +2, Con +0, Int -4, Wis +0, Cha -3
+>
+> Pack Tactics: advantage on attack rolls if an ally is within 5 ft of the target.\
+> Bite +4 to hit, reach 5 ft, 1d4+2 piercing.
+
+## The Bamboo Forest (above ground)
+
+Dense bamboo, 30ft tall. Hard to see more than 10ft in any direction. Paths crisscross through it. A territorial giant snake lives here.
+
+> Giant Constrictor Snake
+>
+> AC 12. HP 60 (8d12+8). Speed 30 ft, swim 30 ft.\
+> STR 19 (+4), DEX 14 (+2), CON 12 (+1), INT 1 (-5), WIS 10 (+0), CHA 3 (-4).\
+> Saving Throws Str +4, Dex +2, Con +1, Int -5, Wis +0, Cha -4\
+> Skills: Perception +2.
+>
+> Bite +6 to hit, reach 10 ft, 2d6+4 piercing.\
+> Constrict +6 to hit, reach 5 ft, 2d8+4 bludgeoning and target is grappled (escape DC 14). While grappled, target is restrained and snake can't constrict another target.
+
+## The Swamp (above ground)
+
+Knee-deep murky water, twisted trees, thick fog. Difficult terrain throughout. Swarms of insects buzz everywhere — annoying but not dangerous.
+
+## The Thornwood (above ground)
+
+A patch of dense, thorny bushes and gnarled trees. Moving through it without following the narrow paths costs 1d4 piercing per round. A family of wild boars roots around in here.
+
+> Wild Boar (3 in the thornwood)
+>
+> AC 11 (natural armor). HP 11 (2d8+2). Speed 40 ft.\
+> STR 13 (+1), DEX 11 (+0), CON 12 (+1), INT 2 (-4), WIS 9 (-1), CHA 5 (-3).\
+> Saving Throws Str +1, Dex +0, Con +1, Int -4, Wis -1, Cha -3
+>
+> Charge: after moving 20 ft straight, first melee hit deals +1d6 damage and target must make STR save DC 11 or be knocked prone.\
+> Relentless (1/day): if reduced to 0 HP by damage that doesn't kill outright, drop to 1 HP instead.\
+> Tusk +3 to hit, reach 5 ft, 1d6+1 slashing.
+
+## The Fungal Tunnel (below ground)
+
+A long winding tunnel carpeted with bioluminescent fungi. The air is thick with spores — CON save DC 10 each minute or sneeze loudly, giving away your position.
+
+## The Bone Pit (below ground)
+
+A cavern littered with old bones. Skeletons occasionally animate — one or two at a time, not a serious threat, just a nuisance.
+
+> Skeleton
+>
+> AC 13 (armor scraps). HP 13 (2d8+4). Speed 30 ft.\
+> STR 10 (+0), DEX 14 (+2), CON 15 (+2), INT 6 (-2), WIS 8 (-1), CHA 5 (-3).\
+> Saving Throws Str +0, Dex +2, Con +2, Int -2, Wis -1, Cha -3
+>
+> Vulnerable to bludgeoning. Immune to poison, exhaustion.\
+> Shortsword +4 to hit, reach 5 ft, 1d6+2 piercing.\
+> Shortbow +4 to hit, range 80/320, 1d6+2 piercing.
+
+## The Echo Hall (below ground)
+
+A long, high-ceilinged cavern where every sound echoes and amplifies. Whispers carry hundreds of feet. Useful for eavesdropping on other teams, but your own conversations carry just as far.
+
+## The Lava Tubes (below ground)
+
+A network of smooth, winding tunnels formed by ancient lava. Warm but not dangerous. Multiple exits make it a good shortcut between areas, but it's easy to get turned around.
+