Thief Skills As Surprise -- Stealth, Part 2

In the first part of Thief Skills As Surprise, I forgot to mention an option to scale difficulties when attempting to move silently or hide in shadows. Instead of adding a level-based bonus, change the surprise chance based on opponent’s level.

When hiding from a monster, compare the thief’s level to the level or hit dice of the monster and consult this table:

Thief vs. Monster	Surprise Roll
Thief 4+ levels higher	3+ on 1d6
Thief +/-3 levels	4+ on 1d6
Thief 4-6 levels lower	5+ on 1d6
Thief 7-8 level lower	6+ on 1d6
Thief 9+ levels lower	fail to surprise

The last two rows are optional, but make it easier to adapt monsters that are harder to surprise.

• If a monster lists a lowered surprise chance (“Surprise only on 1 in 6”,) shift the chance down one row on the table.
• If a monster can’t be surprised normally, but you believe high-level thieves should still get a chance, shift the chance down two rows.

If you feel especially generous, thieves 9+ levels higher than the opponent will automatically succeed.

When using this table, the only modifier to the row is for cover or noise-reduction measures. Even this can be done away with, though: shift up one row for partial cover or any padding/muffling, or up two rows for total cover. I actually prefer this approach to using a level-based bonus.

Note on Surprising Machines: If a thief is trying to hide from a device or anything else that does not have a level or hit dice rating, use the dungeon level as the rating. So, a sound-activated trap on the 5th level can be bypassed a third of the time by even a beginning thief, two-thirds of the time by a 9th-level thief.