Slam Damage is a prefix that turns up on Off Hand, but only on gear tagged bulwark. It gives kitSlamPercent: +10% to +13% at its lowest step, +46% to +50% at its best — and you need item level 116 before the best one can appear at all.
It comes up at weight 5 when the game rolls affixes, never doubles up with another affix that does the same job (kitSlamPercent), and it is what puts Ramming, Battering, Colliding, Earthshaking and Mountainbreaking in an item's name — so you might pick up a Ramming Wand.
No Unique carries it at a fixed number.
Every step
10 steps · lowest to best
| Tier | Needs item level | Gives | Prefix word | Reads as |
|---|---|---|---|---|
| T1 | 1 | +10% to +13% | Ramming | Ramming Wand |
| T2 | 6 | +14% to +17% | Ramming | Ramming Wand |
| T3 | 14 | +18% to +21% | Battering | Battering Wand |
| T4 | 24 | +22% to +25% | Battering | Battering Wand |
| T5 | 36 | +26% to +29% | Colliding | Colliding Wand |
| T6 | 55 | +30% to +33% | Colliding | Colliding Wand |
| T7 | 75 | +34% to +37% | Earthshaking | Earthshaking Wand |
| T8 | 92 | +38% to +41% | Earthshaking | Earthshaking Wand |
| T9 | 105 | +42% to +45% | Mountainbreaking | Mountainbreaking Wand |
| T10 | 116 | +46% to +50% | Mountainbreaking | Mountainbreaking Wand |
Where you will see it
13 bases it can land on