Every minute climbing, a character must make a dice roll using his/her CO + Climbing (including Climbing safely specialism). If the dice roll result is greater than or equal to the difficulty value of the climb, the character climbs safely. If he/she fails the dice roll by less than or equal to five points, he/she loses his/her hand-hold and is hanging on (see Hanging on). If he/she fails the dice roll by more than five points, he/she loses all hand-holds and falls. A falling character will suffer falling damage on impact.
Typical difficulties for climbs are as follows:
| Type of climb | Typical difficulty |
| Fixed ladder | -2 |
| Rope ladder | 0 |
| Knotted rope | 2 |
| Tree | 4 |
| Rock face | 7 |
| Normal building | 10 |
| Sheer smooth face | 15 |
| Wet conditions | Add 2 |
| Crumbly surface | Add 2 |
There is a -2 penalty to the basic value on the dice roll if the character is using only one arm.
For example, Urlik is a good climber with a Climbing skill of 3 and 2 points of specialism in Climbing safely (which is a broad specialism so he gets a +1 bonus for these two points). He has a CO score of +1 and is lightly encumbered (giving a +1 bonus on dice rolls based on CO). His basic value for climbing safely is 3+1+1+1 = 6, which gives him a guaranteed dice roll result of 6. When climbing a rock face (difficulty 7), he can either climb at his normal speed (5 metres/minute) and take some risks, or he can reduce his climbing speed (see Climbing speed) by 2 metres/minute (leaving him with a guaranteed 3 metres/minute climbing speed) and automatically gain a dice roll result of 7.