With the identification of the Cloak of the Manta Ray, this will become an issue very shortly. Here is the ruling, followed by the rationale:
– Monks only can attempt unarmed strikes underwater, although they will suffer all the other usual underwater combat penalties, including those regarding initiative and weapon restrictions (DMG 56). However, they cannot use their special striking abilities (stun, instant death, etc.).
Rationale: Generally, punches are worthless underwater. Monks, though, tap into uncanny forces when making their unarmed strikes. Above the waves, this translates into stunning and killing blows; underwater, it just means the strikes land and do damage despite the water resistance.
The reaction bonus number provided by Dexterity is applied to surprise to negate some or all of the surprise segments granted by the surprise roll. Each point of difference between the opposed sides’ surprise rolls is a segment.
By default, this means that each side rolls a d6 for surprise and the difference is the number of surprise segments. A character with a Dexterity reaction bonus can negate the surprise if that bonus exceeds the die difference. In that case, that one character is not part of combat (i.e., neither attacks nor is attacked) until after initiative in the first normal round.
For combat involving creatures or characters that use other dice or percentages to determine surprise, we will need to roll percentile dice. The article linked below from Dragon Magazine #133 explains how we will resolve these situations.
For example, the Starchie Boyz have a 2-in-6 (33%) chance of being surprised while Chuq is a monk who can be surprised only 30% of the time. Let’s assume the opposing side surprises on the normal 2-in-6 chance. If the party rolls under 29%, Chuq can be surprised if the opposing side rolls 68% or more (5+ segments, minus 2 segments for the party’s roll, minus 2 segments for his reaction bonus which equals 1+ surprise segments). The remainder of the party in this situation would be surprised if the opposing side rolls 34% or more (3+ segments, minus 2 segments for the party’s roll, which equals 1+ surprise segments).
