What is Stack It? The Scale Blackjack Puzzle
Stack It is an additive scale puzzle inspired by classic Blackjack (21). Instead of playing cards, you are dealt physical silhouettes of real-world objects, animals, and architectural landmarks from the Size It Games catalog. Your goal is to build a vertical tower reaching as close to 100.0 meters (or 1.0 m in Micro mode, 1,000 m in Titan mode) as possible without busting.
Every stage tests your mental database of proportions and risk management. With only 2 passes available per stage, choosing whether to stack a mysterious creature or landmark or to lock in your elevation requires razor-sharp scale instincts.
Tactics & Strategy Guide for Stack It
Master the mechanics to maximize your score across all 3 stages:
Anchor your foundation with large items
Early in each stage when altitude is low, stack substantial items (like buses, blue whales, or buildings) to rapidly close the gap.
Save passes for the danger zone
Once your tower passes 75 meters, an unexpectedly massive item like an airliner or landmark will instantly bust your run. Save your 2 passes for the final stretch.
Fine-tune with everyday scale items
Vehicles, trees, and tall animals (like giraffes at ~5.5m or elephants at ~3.3m) are ideal precision builders to reach the 98m–100m zone.
Know when to lock in
A banked tower of 95.0 meters awards 75 points. Greedily attempting another stack when you are already in the 90s risks a total 0-point bust.
Frequently Asked Questions
What is Stack It to 100m and how do you play?
Stack It to 100m is an additive scale estimation game where you stack silhouettes of real-world objects, animals, and landmarks to get as close to 100.0 meters as possible without exceeding it. You have 2 skips per stage and can lock in at any time to bank your points.
What makes Stack It a "Scale Blackjack" game?
Like Blackjack where the goal is 21 without busting, Stack It gives you mystery silhouettes with concealed heights. You must decide whether to "Hit" (Stack) or "Stand" (Lock In/Hold) to reach 100 meters without going over.
How does scoring work in Stack It?
Points are awarded based on final banked altitude: exactly 100.0m earns a 300-point Golden Architect bonus; 98.0m–99.9m earns 100 points; 90.0m–97.9m earns 75 points; 75.0m–89.9m earns 50 points; 50.0m–74.9m earns 25 points; and exceeding 100.0m results in a bust (0 points). A run consists of 3 stages for a cumulative score.
What are the Micro and Titan modes in Stack It?
In addition to the standard 100-meter tower, Stack It offers Micro mode (stack microscopic items to reach 1.0 meter) and Titan mode (stack mountains, planetary features, and massive structures to reach 1,000 meters).
Can I play in Imperial units (feet)?
Yes! Toggle between Metric (100.0 m) and Imperial (328.1 ft) units anytime using the unit switch. All silhouettes, ruler ticks, and elevations update seamlessly in real time.
Is Stack It to 100m free to play online?
Yes, Stack It is completely free with no downloads or account sign-ups. Play directly in any desktop or mobile browser.
Games
Explore more interactive scale estimation challenges in the Size It Games suite: