Meat, Wood, Coal and Iron, plus gems, speedups and Fire Crystals.
TL;DR Gems → VIP and value packs, not resource refills. Speedups → only during scoring events. Resources → keep enough to finish your next Furnace step.
💎Where to spend gems
Priority
Spend on
Avoid
Better
VIP upgrades, the Lucky Wheel, Chief Stamina in the VIP shop
Resource refills
Situational
A second construction queue (a one-time store pack)
Buying a queue you can’t keep busy
Avoid
Instant speedups on short timers
Using gems as a shortcut
⏩Speedups
Don’t use speedups just because a timer is long.
Do stack them for Hall of Chiefs, King of Icefield and SvS prep days on the matching theme.
General speedups are the most flexible; spend specific ones (build/research/training) first.
🎁Free stuff
Redeem gift codes from official channels (Discord, socials) through the in-game or official redemption page.
Free store packs add up. Claim them every day.
Light spenders are usually pointed at the monthly value packs and the one-time queue packs.