Core GameSystems

• Danger zones correspond to the centres listed in `constants/gameSettings.ts` (10, 19, 24, 27, 32, 39, 44, 52, 58, 65, 68, 72, 84, 87, 93).
• Sunny keeps the zone to that tile only. Snow grows the zone one tile downhill. Blizzard extends one tile both uphill and downhill.
• When a wrong answer happens on any active tile, the player document receives `pendingAvalancheId` and the host board animates the matching path.
• You can enable or disable specific centres by updating the `dangerZones` array on the game document – the Options modal handles this for you.

Tip: Need a calmer round? Set the weather to Sunny and clear the `dangerZones` array except for the tiles you want to emphasise.

• Checkpoints prevent players from sliding all the way back to the base after an avalanche.
• Default frequency is every 25 tiles. The Options modal lets you specify up to eight custom checkpoint positions.
• When a player moves, the client recalculates `lastCheckpoint` and writes it to their document so resets are instant if an avalanche hits.
• The host board displays checkpoints as yellow markers, helping you narrate when someone reaches a safety milestone.

Tip: In teaching scenarios, add more checkpoints so beginners do not lose motivation after a single mistake in the higher altitude zones.

• Whenever a player answers correctly, the client increments a local streak counter. Three correct answers inside the configured window unlock the shield.
• The shield window defaults to the first half of the question set, but the host can set `powerupsConfig.shieldOfferStartIndex` and `shieldOfferEndIndex` to fine-tune it.
• Once a shield is unlocked, the player document stores `powerups.shield = 'available'`. The next pending avalanche gives that player the shield prompt.
• Spending the shield writes `shieldUsedFor` and `shieldUsedAt` back to Firestore so the host log shows who burned their protection.

Tip: Encourage teams to hold shields for the high-number danger zones (65+). Losing 20 tiles late in the game hurts more than an early mistake.

• Each player receives a personalised Map & Compass spawn between tiles 1-15. The placement avoids checkpoints and danger zones so the event stays reachable without extra tweaking.
• Landing on the marked tile opens a Map & Compass challenge modal. Answer correctly to add the tool to your inventory; miss it and the event resolves with no penalty.
• If you already own the Map & Compass, replaying the event grants a small +1 position confidence boost while keeping the item equipped for later encounters.
• Inventory records live on the player document (`inventory.map_compass`). Hosts can see when a player secures the tool and plan fork-side support accordingly.

Tip: Highlight the early-event when onboarding new players—securing the Map & Compass makes the mid-game fork dramatically safer.

• Fork tiles appear around positions 31-50 and trigger once per player. Choosing left or right without tools has a 50% success rate and moves you forward 4-8 spaces on a win.
• Using the Map & Compass reveals the safe route instantly and awards the same 4-8 space advance without risk, consuming the tool for that decision.
• Picking the wrong path launches a side quest instead of an immediate penalty. Players can seek a hermit (2 quick answers to avoid a setback), forge ahead alone (three answers for a +10 win or -15 loss), or solve a 3×3 sliding puzzle if they held onto the Map & Compass.
• All fork outcomes update the player document with telemetry and event flags so the host log captures who chose which option and how far they moved.

Tip: Coach teams to save their Map & Compass until the fork shows up—skipping the side quest keeps momentum and protects late-game streaks.

• Tunnel offers now open up to three times per match, usually between positions 51-70 (configurable via `tunnelOfferWindow`).
• Offer frequency scales with performance: trailing players get up to a 50% chance after a correct answer, while leaders see the original 10% baseline.
• Successful tunnel answers leap players ahead 8-24 spaces by default, with deficit-aware math capping jumps at the summit so catch-up feels fair.
• Declining or missing the tunnel simply advances to the next question—the progression system adds the tunnel question to the normal cycle so nothing is lost.

Tip: Encourage players in the back half to accept tunnels—the adaptive jump is tuned specifically to close large gaps without handing out instant wins.

• The Options modal updates the live game document. All changes propagate immediately to every connected client.
• The Events feed is simply the `games/{gameId}/events` collection. It now records Map & Compass pickups, fork outcomes, and tunnel jumps in addition to avalanches and manual host actions.
• Audio controls on the host board manage the avalanche and background tracks. They run entirely in the browser – no extra services required.
• Use the log to troubleshoot desync. If you see a player trigger an avalanche but they say nothing happened, have them refresh and rejoin using the same code.

Tip: Need to test without players? Add yourself as a player in a second tab, start the game, and use the Options modal to fire manual avalanches while watching the logs.