All weapon skills cross-train with at least one other weapon skill. Experience invested in the main skill gives a direct 40% experience bonus to the secondary skills. The following weapon skills cross-train with each other:
- Short Blades and Long Blades cross-train each other
- Axes and Staves cross-train Polearms and Maces & Flails
- Maces & Flails and Polearms cross-train Axes and Staves
- Throwing and Slings cross-train each other
In practice, this allows characters who specialize in a weapon type early on to diversify their arsenal by the mid- or late-game, should they come across an attractive weapon.
Prior to 0.15, cross-training gave an aptitude bonus to the secondary skills, rather than a direct experience bonus.