The last in the Thief Skills As Surprise series (list of links below) deals with the remaining thief skills, trying to judge which ones qualify as a surprise situation and which do not.
Strike Silently from Behind is an obvious choice for a surprise-based ability. The original rules handle this as a damage multiplier. I prefer to add the surprise roll result, plus the thief’s level, to the standard damage roll. This makes the damage higher than usual for 1st level thieves and keeps the minimum and average damage high as the character’s level advances, but reduces the max damage.
|Level||Greyhawk damage||My damage rules|
|1||2-12 (7 average)||7-13 (10 avg)|
|5||3-18 (11 average)||11-17 (14 avg)|
|9||4-24 (14 average)||15-21 (18 avg)|
|13||5-30 (18 average)||19-25 (22 avg)|
Climb Walls may seem less obvious, until you consider what is going on. Anyone can climb a ladder, a tree, or a rope. They can’t climb a sheer wall without either (a) throwing a grappling hook over the top of the wall, or (b) hammering iron spikes into the wall. Both of these make noise, negating surprise. A thief, in contrast, climbs walls without equipment. It is, basically, Climb Silently. One could argue that we should just dispense with the table of percentages for Climbing and just note that thieves can climb without equipment and use their Move Silently ability while climbing.
The other two thief abilities, reading treasure maps and magical inscriptions, are obviously not related to surprise. They are just extras thieves pick up to make their tasks easier.
Thief Skills As Surprise Series: