Bone Shards•Attack

Is Bone Shards good in Slay the Spire 2?

Bone Shards is an uncommon Necrobinder attack in Slay the Spire 2. In combat it resolves as: If Osty is alive, he deals 9 damage to ALL enemies and you gain 9 Block. Osty dies. It currently underperforms most alternatives, sitting at D tier in our Slay the Spire 2 card rankings.

Across 187 recorded runs, decks running it win 15.1% of the time, comfortably clear of the 14.0% average, by 1.2%. It’s a more selective pick, turning up in just 1.6% of decks that could run it. Taken in 17.9% of its offers, it still trails on the pick-versus-skip split: 14.7% for runs that took it against 25.8% for runs that left it, a -10.4% pick lift over 157 decided runs. Necrobinder players keep it in 8.4% of their runs, so it’s a familiar sight in those decks. On average it shows up 1.1 times in the decks that take it.

It performs best next to Putrefy — together they post a +21.9% swing in win rate. It also has strong chemistry with the relic Strawberry, which moves its win rate by +20.4%. At 1 energy, it’s upgraded in 27.9% of runs and usually joins the deck around floor 13.

Upgraded, it gains +3 OstyDamage, +3 Block, which is why so many decks invest a rest-site upgrade in it. That’s 28 wins, 157 deaths, and 2 abandoned runs with it in the deck. The encounter that most often ends a run carrying it is The Insatiable Boss, which closes out 5.9% of its appearances. Read on for Bone Shards’s complete synergy, class, and threat breakdown to decide whether it earns a slot in your Necrobinder run.

Pick or Skip: Bone Shards

Out of 918 recorded offers Bone Shards is taken 17.9% of the time, and taking it is worth -10.4% in pick lift — 14.7% for runs that picked it against 25.8% for runs that skipped, across 157 decided runs.

Taken 164 times out of 918 offers.

Pick rate when offered counts offers, not runs: out of every time the game put this in front of a player, how often it was taken. It is not the same number as the share of runs that end up containing it.

Pick lift is the sample-adjusted gap between runs that took the option and runs that passed on it. It is the fair way to rank choices, because raw win rates put the smallest samples on top.

When to Pick Up Bone Shards

Bone Shards is strongest when it joins the deck in Act 3, where runs win 25.0% across 12 runs — one of 3 recorded pickup windows.

Win rate of runs by the act Bone Shards entered the deck. Acts that have not reached the sample floor show their run count only.

Best Cards to Pair with Bone Shards

Ranked by win-rate lift, Bone Shards performs best alongside Putrefy (+21.9%), Neurosurge (+18.8%), and Debilitate (+17.9%).

Putrefy+21.9%40 runsNeurosurge+18.8%21 runsDebilitate+17.9%35 runsDredge+17.6%17 runsFear+16.1%30 runsCountdown+13.6%37 runs

Based on small co-occurring samples — treat these as early signals, not final verdicts.

Bone Shards Win Rate by Class

Bone Shards is drafted only by the Necrobinder, where it holds a 15.1% win rate across 187 runs.

The Necrobinderappears in 8.4% of its runs (187 tracked)

Best Relics for Bone Shards

Bone Shards pairs best with the relics Strawberry (+20.4%), Bone Flute (+18.9%), and Candelabra (+18.8%), ranked by win-rate lift.

Strawberry+20.4%28 runsBone Flute+18.9%15 runsCandelabra+18.8%18 runsCentennial Puzzle+17.8%28 runsLantern+17.7%22 runsPotion Belt+15.2%28 runs

Based on small co-occurring samples — treat these as early signals, not final verdicts.

Bone Shards Card Details

Bone Shards is an uncommon attack costing 1 energy; it’s upgraded in 27.9% of runs and usually picked up by floor 13.

If Osty is alive, he deals 9 damage to ALL enemies and you gain 9 Block. Osty dies.

Upgrade: +3 OstyDamage, +3 Block

What Ends Runs with Bone Shards

Bone Shards’s most common run-enders are The Insatiable Boss (5.9%), Kaiser Crab Boss (5.9%), and Decimillipede Elite (5.3%).

• The Insatiable Boss5.9% of runs
• Kaiser Crab Boss5.9% of runs
• Decimillipede Elite5.3% of runs
• Infested Prisms Elite4.8% of runs
• Test Subject Boss4.8% of runs

See Also

Compare Bone Shards with the rest of the best Slay the Spire 2 cards, relics, and classes below.