The Diamond (Sly 3)

Lore & Background

In Sly 3: The Big Score, Sly Cooper's crew is on a grand tour of the world's most prestigious and heavily guarded collections, pulling off heists that range from museum galleries to high-security vaults. The Diamond fits squarely into this tradition: a single, gleaming objective surrounded by layers of security that demand the team work in concert.

The mission reflects the game's core design philosophy—each heist is a self-contained puzzle of patrol routes, alarm triggers, and character-specific abilities. Sly's ability to roll, climb, and hide in shadows is the backbone of the approach, while Bentley's gadgets (such as the grappling hook and the egg launcher) open shortcuts, and Murray's strength clears barriers that would stop the others. The diamond itself sits at the end of a gauntlet of these interlocking systems.

Within the narrative of Sly 3, these heists are not merely gameplay set-pieces; they are the means by which the crew funds their operations and proves themselves against rival thieves and corrupt security forces. The Diamond, as a high-value single-item target, represents the kind of job that draws the most serious opposition and the tightest security protocols.

In Their Own Story

The vault room smelled of cold steel and recycled air. Bentley's voice crackled through Sly's earpiece, static threading between words: "Sly, the guard rotation just shifted. You've got maybe nine seconds before the next one crosses your line of sight."

Sly didn't need nine seconds. He needed three. He rolled beneath the patrol's flashlight beam, felt the tile groan under his paw, and pressed his shoulder against the glass case. The diamond inside caught the overhead light and threw a tiny constellation across the ceiling—blue-white, almost alive.

"Murray," Bentley said, "the support beam on the east wall. Now."

A dull thud. Dust rained down. Sly was already inside the case, fingers closing around the stone, pulling it free with a soft click of the magnetic lock disengaging. He tucked it into his bandana, rolled out the way he'd come, and was three platforms up before the first guard even turned his head.

"Clean," Bentley said. Just that. One word. The best kind of word.

Reader's Guide

Target: A diamond housed in a glass case within a guarded interior space. The case is typically protected by patrol routes, alarm sensors, and at least one heavy obstacle that requires Murray's strength to bypass.

Approach: The standard route has Sly scouting the patrol pattern from a vantage point, then executing a timed run through the security corridor. Bentley can deploy a gadget to distract or disable a specific sensor, buying Sly a window to reach the case. Murray is needed to break through a structural barrier (a beam, a locked gate, or a reinforced wall) that blocks the direct path to the diamond.

What makes it tricky: The patrol timing is tight, and a single misstep triggers an alarm that resets the section. The character-switching requirement means you cannot simply run the whole route as Sly; you must plan where Bentley and Murray are positioned before committing to the final approach.

Alternate routes and hidden objectives: Sly 3 rewards exploration. Look for alternate entry points—vents, rooftop access, or side corridors—that let you bypass the main patrol entirely. Collectible items (gears, blueprints, or character-specific pickups) are often tucked in areas off the critical path. Completing the heist without triggering any alarm, or completing it with all three characters contributing, can unlock bonus content or a higher score rating.

Tip: Before your first run, spend time as Sly simply observing the guard pattern from a safe distance. Most of the difficulty in this heist comes from rushing the timing rather than from the obstacles themselves.

Did You Know?

• Sly Cooper 3: The Big Score was developed by Sucker Punch Productions, the same studio behind the original Sly Cooper and Sly 2: Band of Thieves.
• The game's three playable characters—Sly, Bentley, and Murray—each have distinct movement and combat abilities, and heists like The Diamond are designed to require all three to be completed efficiently.
• Sly 3 introduced a more open, multi-city structure compared to its predecessors, with heists spread across different international locations rather than a single continuous level.
• Bentley's gadget toolkit in Sly 3 includes tools like the grappling hook and the egg launcher, which can be used to create shortcuts or disable obstacles during heists.