Cohesion Test Query

[rbodleyscott]

gamercb sent me the following PM.

Hello Richard,

You say that the RNG is fair and luck is not a significant factor so can you tell me what the chances of the following happening in a single turn.

A Noble Lancers that is fragmented is fighting a Warband to the front and Noble Archers to the rear. It lose to the Warband and takes a cohesion test at a -4 modifier and holds. It then fights the Noble Archers and has to take a 2nd cohesion test at -5 and holds again.

A Noble Archer in another combat had to take a Cohesion test with a 0 modifier and dropped a level. Also a Armoured Noble Lancer charged an Irregular Foot with a +32 POA (50% chance of a win) and the result was 6 and 12 casualties respectively.

I am not an experienced Ancient wargamer and I find it strange that Lancers do so badly against infantry when they charge. It said in one charge that I looked at that I had a 2% chance of winning a charge.

Thank you,

I am posting my reply below in case anyone else finds it useful.

[rbodleyscott]

Hi gamercb,

You say that the RNG is fair

It is.

and luck is not a significant factor

That I have not said. I have said that skill generally triumphs overall, not necessarily in individual combats. This is by design. When the RNG goes against the more likely outcome, that simulates all sorts of unpredictable historical events that could not otherwise be simulated. Also, it means that a plan must take into account parts of it going wrong, and increases the value of reserves.

A Noble Lancers that is fragmented is fighting a Warband to the front and Noble Archers to the rear. It lose to the Warband and takes a cohesion test at a -4 modifier and holds. It then fights the Noble Archers and has to take a 2nd cohesion test at -5 and holds again.

Bear in mind that because both tests are for close combat in the same turn, the second cohesion test uses the same random score as the first, to simulate one cohesion test being taken after all close combats are resolved, as happens in the tabletop game. (Otherwise, if multiple completely independent cohesion tests were taken, the whole cohesion test system would need to be completely rebalanced to prevent a much higher overall failure rate than we intend). So, with one additional negative modifier, it would only fail the second test if it only just passed the first one.

The chance of a Superior unit passing a test at -5 is 11.3%.

See

https://steamcommunity.com/sharedfiles/ ... =735499412

(Pike and Shot uses the same CT system - there are some different modifiers, but the chances of failure at a certain total modifier level is the same in P&S and FOG2).

Because the same roll is used for both tests, the overall chance of passing both tests (not each test) is therefore 11.3%.

If they used separate rolls, the chance of passing the first test would be 22.7% and the chance of passing the second would be 11.3%, giving an overall chance of passing both tests of 2.6%, which would indeed be rare, and which is perhaps what you were expecting. But as they don't use separate rolls, the chance of passing both tests is the same as the chance of passing the worst one i.e. 11.3%, not 2.6%.

A Noble Archer in another combat had to take a Cohesion test with a 0 modifier and dropped a level.

14.7%

I am not an experienced Ancient wargamer and I find it strange that Lancers do so badly against infantry when they charge. It said in one charge that I looked at that I had a 2% chance of winning a charge.

Ancient cavalry, including lancers, were not usually able to ride down steady competent infantry frontally.

Richard

[kronenblatt]

It was. Useful, that is. Thanks R.!

[LuciusSulla]

Bear in mind that because both tests are for close combat in the same turn, the second cohesion test uses the same random score as the first, to simulate one cohesion test being taken after all close combats are resolved, as happens in the tabletop game. (Otherwise, if multiple completely independent cohesion tests were taken, the whole cohesion test system would need to be completely rebalanced to prevent a much higher overall failure rate than we intend). So, with one additional negative modifier, it would only fail the second test if it only just passed the first one.

Just learned this rule. What about other CTs in the same turn? I would assume that CTs from different sources use different rolls (e.g., ranged attack causing casualties v. losing close combat). But what about multiple CTs from the same source (e.g. multiple rounds of ranged attack suffered; multiple adjacent friendly units routs; frag unit being charged multiple times)?

[rbodleyscott]

Bear in mind that because both tests are for close combat in the same turn, the second cohesion test uses the same random score as the first, to simulate one cohesion test being taken after all close combats are resolved, as happens in the tabletop game. (Otherwise, if multiple completely independent cohesion tests were taken, the whole cohesion test system would need to be completely rebalanced to prevent a much higher overall failure rate than we intend). So, with one additional negative modifier, it would only fail the second test if it only just passed the first one.

Just learned this rule. What about other CTs in the same turn? I would assume that CTs from different sources use different rolls (e.g., ranged attack causing casualties v. losing close combat). But what about multiple CTs from the same source (e.g. multiple rounds of ranged attack suffered; multiple adjacent friendly units routs; frag unit being charged multiple times)?

There are separate shared Cohesion rolls - for melee, and for ranged attacks.

Multiple melees share the same roll.

Multiple rounds of shooting received share the same roll, but with the following caveat: Internally, when a unit shoots it actual fires 2 volleys (to simulate shooting in both players' turns) and there are separate stored random rolls for each of those volleys, and separate morale tests for each volley.

Seeing adjacent routs, or generals lost, or being charged while fragged - these are separate independent rolls.