I quote OLF from the thread he referenced in his previous reply,
Everything. Historically, the spear and its variant were used not because they merely gave a chance to strike first (initiative modifiers) but because they allow their user to keep their opponent at range. It's not "I may strike you first" but "you cannot touch while I can hit you". Reach is very important in combat, and the above missile point is just about that.
This is significantly stronger than a simple initiative bonus. It means that skilled long weapon users, if they are not out-skilled, can keep an opponent at bay until the situation changes.
I have not tested what follows in any way, mind you, but it would likely go like this [L uses the longer weapon, S uses the shorter one]
- initiative is rolled, with L getting a bonus as usual. Whoever gains initiative is at preferred range.
- if L has range (and thus initiative) and hits S (inflicts a crit, I'd say), then S cannot close and thus cannot attack. The range is unchanged until the following round.
- if L is at range and does not hit S, then S can try to get close: if their attack hits (inflicts a crit), then they have gained the upper hand and the preferred range is now that of the shorter weapon.
- if S has range (and thus initiative) and hits L, then L cannot fall back and is limited in his own attacks (he can attack because longer weapons can be used at shorter ranges - however, the shaft is typically used instead of the blade). L can attack with an appropriate negative modifier, but will only regain range and initiative if they can score a crit that prevents S from attacking (must parry, stun, pushed back...).
If the S has range but does not hit L, then L is limited in his own attacks as above, but if they hit (any critical), then they regain preferred range.
Basically, this translates into a back-and-forth where both opponents try to gain the advantage / keep it when they have it, with the longer weapon user being favourite to have an initial situational advantage (and also having the benefit of being able to use their weapon, albeit at a penalty, at an unfavourable range).
The reason why I would only consider a crit (any crit) as a "true hit" is because of heavy armour: those wearing heavy armour trade mobility for durability, yet in this case they could not get the benefit of this trade if a "true hit" was any hit result (heavy armours are hit at lower combat result values). With this definition of "true hit", the lightly armoured opponent will have to actively parry and dodge to avoid being hit by the longer weapon (because most hits are crits against light armours) while heavy armour opponents can "take it" and trust their armour to suffer only a bruise if an attack connects, giving them an opening.
