Since I actually took possession of the Original D&D reprints, I’ve been reading the booklets through from the beginning, something I haven’t done since, well probably ever. I’ve found an interesting tidbit regarding surprise that I did not previously know of. This is from the 3rd volume, The Underworld and Wilderness Adventures (UW&WA), emphasis added:
Surprise: A Condition of surprise can only exist when one or both parties are unaware of the presence of the other. Such things as ESP’ing, light, and noise will negate surprise. If the possibility for surprise exists roll a six-sided die for each party concerned. A roll of 1 or 2 indicates the party is surprised. Distance is then 10-30 feet.
Surprise gives the advantage of a free move segment, whether to flee, cast a spell or engage in combat. If monsters gain surprise they will either close the distance between themselves and the character(s) (unless they are intelligent and their prey is obviously too strong to attack) or attack. For example a Wyvern surprises a party of four characters when they round a corner into a large open area. It attacks as it is within striking distance as indicated by the surprise distance determination which was a 2, indicating distance between them was but 10 feet. The referee rolls a pair of six-sided dice for the Wyvern and scores a 6, so it will not sting. It bites and hits. The Wyvern may attack once again before the adventurers strike back.
Note the last sentence. This is interesting because it says that surprise really nets the party or the monster two free actions – a move and attack, two attacks (if the initial distance is 10 feet), or two moves. presumably the latter would be used by a monster that wanted to flee a much stronger party, since at these close distances, the first move would always bring the monster within melee distance if so desired. I don’t believe this is a typo, since that last sentence is very clear.
I can see how this might unbalance things in favor of the monsters, since a party in a dungeon would typically have torches or other light sources that would allow them to be surprised, but never allow them the benefit of surprise, at least while entering any open area. Two rolls of 1-2 on a d6, and the monster gets two free attacks, presumably on the lead adventurers. This gets even worse when you combine it with the other surprise rule in OD&D:
There is a 25% chance that any character surprised by a monster will drop some item. If he does, roll for the possibilities remembering that only these items held could be so dropped.
This is also from UW&WA. Lead adventurers don’t typically carry torches, at least in my games the front ranks are the strongest fighters, and they walk around with weapons drawn and ready, the middle ranks have the torchbearers. So that leaves a weapon to be dropped by the party’s strongest fighters 25% of the time. This could get ugly very quickly for the party – in the worst case, a monster would get two free attacks, one or more of the party’s fighting complement would drop their weapon and have to waste a round of combat picking it up, giving the monster yet another unanswered attack, even if it lost initiative.
I think most people just ignore these rules, although I’d be interested to hear from those of you that do use them. The OD&D retroclones I’m familiar with (Swords & Wizardry and Delving Deeper) allow only one unanswered surprise action, although both do have the dropped item rule. I didn’t actually play OD&D back in the day, but I know even when we played AD&D 1e in the 80s, we ignored the detailed surprise rules in that edition and just gave one free action to whoever gained surprise.