"Mechanics for Surprising Sentries, Guards, Pickets, etc. ?" Topic

I've been looking to create AWI scenarios from a number of raids that relied on surprising and overpowering sentries.
In "real life", the raiders were wildly successful in doing so, and accomplished their missions. But such an outcome makes for a lousy wargame.
You say: don't choose those for a scenario.
I say: But I really want to do them, as they occurred on ground I know. One example: Meig's raid on Sag Harbor, L.I.

Any ideas on how to handle sentries being approached by raiders covered by darkness, mist or incredibly good "sneakiness"?
When does the sentry "spot" them, if at all? A die roll?
How to make it so the garrison might get notice and thereby make a game of it?
Am I looking for an impossibility?

Any type of challenge test should work.
Defender rolls X dice based on how alert he is.
Attacker rolls Y dice based on how skillful he is.
Bonus dice for fog (harder to hear, reduced vision), negative dice for dry vegetation (harder to be quiet).

Add up the dice for each side:
Defender rolls 2x the attacker: aware, alerts the guard and attacks first
Defender rolls higher: aware, does not alert the guard and melee as normal
Attacker rolls higher: gets 1 free attack then melee as normal, chance each round to alert the guard
Attacker rolls 2x higher: Defender is removed from play, no chance to alert the guard

=================
Or a simple roll off between the two then a "What happened" random event type roll:
Defender won, roll 1d6: 1-2 = alerts the guard, 3-4 = rushes in to attack first, 5-6 = alerts guard and rushes to attack first
Attacker won, roll 1d6: 1-2 = defender killed, 3-4 = defender captured, 5-6 = defender killed and hidden (no chance of discovery later in the game)

Look at Eutaw Springs. A British foraging party was captured by the advancing Patriot. They were neither armed, nor supported.

I think it's the wrong approach to "guarantee" surprise. It's assuming your opponent is going to play dumb.
In the case of ES, make up an arbitrary number from 1-100 that reflects your opinion of Greene's intelligence gathering, scouting, etc.
The "Greene" player can evaluate the position, and decide if he wants to rush the position, risking disorder, or sneak up.
Whatever.
Then roll a D100 to see if the foragers are prepared or not.
Just a guess.

But try not to guarantee that the side caught flat footed will make the same mistakes. I can make my own, thank you very much.

Stry & John-
Thanks. Food for thought and good ideas.

John- Exactly. I don't want "guaranteed" surprise. Who wants to play the defender in that game?

(although I'd hate to see Meigs get slaughtered)

If you don't mind a system where the attacker is approaching on paper rather than on the board, and you have an umpire it is not hard to do.

The defender sets up his sentries. Each turn the attacker moves. The defender then gets to roll to see how many of his sentries are watching. For each one that is the defender then gets to designate a direction the sentry is looking. If the path crosses the attacker's path for the turn the umpire notes it. After all sentries have finished the umpire then rolls to determine whether the sentry successfully sounds the alarm. If successful the attackers forces are then placed on the board.

The attacking player could also elect to silence sentries. This would also be done off board with the umpire rolling to see if it is successful. One option for the outcome would be that the sentry was taken out but was able to give the alarm. If a sentry was silenced the defender is not notified unless/until the officer of the guard approached the sentry post or ran across the attackers.

If no alarm is given then when the attackers troops reach a certain point his figures are placed on the board. It then becomes a scramble to see whether the defender can organize his troops before they are overwhelmed.

If you want to add to the complexity allow the defenders to have a sentry post not represented by a figure on the board and allow the attackers to have "covered ways" where they won't be spotted even if the defending sentry looks in the right direction as the attacker approaches.

Bill-
More good ideas!
With map movement, one gets "real" surprise.
Defender initially has no idea where attacker is.

With my games, based on obscure skirmish actions, its unlikely the players will know the historical events in advance.

Heh. For Bill's ideas, when a defending sentry is silenced, don't remove him from the board, let the player think he's still there. Remove that sentry when the alarm is raised…Surprise!

If you want to have some player input into sentry alertness as well as some sort of die roll for the sentry spotting the attackers, give the defending player a limited number of chits that he can spend on increasing sentry alertness. If the player uses them for that purpose, then reduce his effectiveness in other matters-the OOD is so busy making sure the sentries are alert that he neglects other duties-maybe a chance of a delay in turning out the rest of the guard force in case of an alarm.

You can add yet another level by having
-civilian units (controlled by the referee),
-friendly units (like from a neighboring unit, not in your chain of command, controlled by the referee),
-false units (i.e., a hostile unit pretending to be civilian or friendly), and
-more granular (flowcharted) sentry spotting effects.

For example, the sentry spotting effects could be something like this:

1. Looks like nothing is in the sentry's sector.

Result: Any unit actually there is not spotted and can move using hidden movement.

2. Something is in the sentry's sector, but the sentry can't identify it.

Result: Sentry makes a morale/reaction check. This could result in: running away; sounding the alarm; freezing for the rest of the turn; engaging the oncoming unit; or doing what a sentry normally does, shouting the challenge: "Halt! Who goes there?"

Response to challenge: Any unit may respond correctly or incorrectly to the challenge, but of course a friendly unit is more likely to respond correctly than a hostile unit, and civilian units are wild card. Did the civil affairs officer tell the locals how not to get shot by accident? Work that out beforehand, maybe with a reaction table.

Sentry's response to incorrect or no response to challenge: morale/reaction check.

Of course, there may not actually be a unit there, and the sentry is just challenging a moose that stepped on a branch. That's probably going to lead to your entire command mobilizing to neutralize the moose threat.

(Hey, don't make fun of the moose threat. I once saw a tour bus in Finnish Lapland that a moose had wrecked by letting the bus hit it. The moose was kind of banged up, too, but the bus was a complete write-off.)

The situations where the sentry spots a unit and identifies it (correctly or not) are left as an exercise for the reader:

3. The sentry spots and identifies (correctly or not) a unit as a civilian unit.

4. The sentry spots and identifies (correctly or not) a unit as a friendly unit.

5. The sentry spots and identifies (correctly or not) a unit as a hostile unit.

Note that in every case, the sentry might be wrong. There might not be a unit there at all, or the unit might actually be something else, such as a false unit, i.e, a hostile unit posing as civilians or friendlies, or even a friendly unit mistaken for enemy. What happens then should be worked out in advance on a reaction table. ("Oh, blast, I rolled a 1 and the sentry thought the wagon was full of rebels and bayoneted two sheep and a keg of ale.")

The intruder force might send a single soldier in civilian clothes ahead of the main force to distract or eliminate the sentry, especially if it knows the correct civilian response to the challenge of the evening.

The second post here:

TMP link

Gives a way to distribute forces that sneak up on each other. It consolidates a bunch of drudgery into the important bit – where are forces when they start to find each other, and subsumes a lot of decisions that would be poisoned by God's Eye View knowledge.

Thanks all!

I have no problem with the issue of ambushes, senators and so forth as I umpire or GM a double blind skirmish game. The players have no need to fiddle with the action and combat carts as they don't get to see the dice results, although they do have according to the charts and rule, for all the good that will do them as they won't know what's going on unless their active player figure is in a position to view the action.
The player, through his figure, transmits orders to his command and I roll the dice and consult the charts for the results.
No fuss!
I know that the gamer would like micromanage, too bad,