DIVM, you probably know this already, but for newer players:
Rallying of non-steady units is a two-step process:
Step 1:
- A routed unit without a general has a 20% chance to attempt to rally.
- A disrupted or fragmented unit without a general has a 40% chance to attempt to rally.
- A unit with a general has a 100% chance to attempt to rally.
- An autobroken unit (with or without a general) can never attempt to rally, and will disperse in the rally phase at the beginning of your next turn (Richard, please correct me if this is incorrect.)
- A unit that is being pursued or suffered >10% losses from shooting in the previous enemy turn cannot attempt to rally, even with a general - which is why it is useful to have light cavalry to chase down the fugitives and possibly even kill the general, if there is one.
If you don't have light cavalry available, then use your foot skirmishers to hopefully inflict enough casualties each turn to keep them running.
If neither are available, you can use non-light cavalry to pursue (if they aren't already), but use your judgement - your cavalry might be better used to turn back and hit other engaged enemy units in the flank or rear. You probably wouldn't want to deliberately use expensive cavalry like cataphracts or armoured lancers/xystophoroi to pursue routed enemy skirmishers unless they had absolutely nothing else better to do.
But a routing "Superior" or "Elite" enemy unit with a general (for example, Roman Praetorian or legionary cohorts, Veteran pike phalanxes, picked warbands, cataphracts, etc.) [Edit: clarification per Richard's post below - with 50% or more of its original strength]? Absolutely pursue those guys with any cavalry available, as they are very likely to rally (because of the general, and because of their quality, see the modifiers in Step 2 below.)
Even large "Average" units like regular pike phalanxes are worth pursuing, because they count for more rout % points than regular-size units.
If you play FOG2 Medieval, ALWAYS pursue routed Swiss keils if possible, for all the reasons above - very large size (therefore more rout % points), "Superior" quality - and in the later Swiss armies, the proportion of generals to keils is higher than in other lists (since there are fewer keils), so quite often there will be a general with a routing unit. If you don't or can't pursue them, there's a pretty good chance you will regret it.
- If a routed unit has not rallied after three turns (previously it was five turns), it will automatically disperse.
Step 2:
- If the unit attempting to rally passes Step 1, then the game system rolls two six-sided dice (2D6) for the rally attempt.
- If the modified dice roll is "6" or higher, then the unit goes up by one level (Routed to Fragmented, or Fragmented to Disrupted, or Disrupted to Steady.)
- Modifiers : -1 to the roll if the unit is Disrupted, -2 if Fragmented, -3 if Routed. In addition, Untrained troops re-roll 6s, Superior troops re-roll 1s, and Elite troops re-roll 1s and 2s.
- [Edit] Also -1 if unit is below 75% of original strength (per Richard's post below.)
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DIVM,
When you observed the higher number of routing troops rallying than before - were there generals with them? What quality were the units?
Even if there weren't generals and these were average units, just from pure chance alone there may be runs of good rolls and more units will rally, or a run of bad rolls and they don't.
When my units rally, it's a sign of divine favor and I absolutely deserved it.
When my opponent's units rally, it's "$#@!? bulls**t!" and the game must be rigged
