Missing an encounter in an Adventure Path. How to compensate?

[Darkfire142]

As you know Adventure Paths often can have numerous encounters that can be bypassed through player actions. This could be unintentional as the PC's might chose to not go down a certain tunnel on the route and not backtrack (Thus missing potential XP and Loot). This also could be intentional as the PC's might be forewarned of some danger and bypass the encounter through stealth, navigation or quick thinking. This in the end might mean that the PC's will miss out on vital gear and experience that would leave them either without the proper tools for a future encounter or underleveled due to lower amounts of XP.

A good example of this is in the Dragonlance Adventure Path. Basically the PC's have a goal to navigate toward an elven encampment deep in the sewers. In the sewers there is a Shield of Bashing and a +1 Sword but both are encounters they might miss completely by accident (By not entering the tunnels with these encounters) or intentionally (Such as seeing a room full of spider webs and deciding to take an alternate route). If the PC's do not get the shield or the sword they will have no magical weapons in a future dungeon that has Shadows, Wraiths and a Demon that can't be efficiently fought without magical weapons. So what can a DM do to steer players towards vital encounters or make up for missed opportunities in an Adventure path?

[tonyz]

Come up with new encounters, of course. APs are frameworks for the GM to work within, not straitjackets that must be played exactly as written.

[ryric]

Generally, I give XP for bypassed encounters if the PCs deleiberately take steps to avoid it. I also give XP for peacefully resolving encounters that are nominally combat.

As far as treasure goes, I usually don't make up treasure for missed things. Specifically for the Dragonlance Age of Mortals path,

Spoiler:

I remember that there is another magic weapon available near the same time as the shadow, a +1 shocking burst longsword, IIRC. The PCs might meet the shadow first, but I think it provides a good lesson in running away when outmatched. I had the shadow not wanting to come upstairs during the daytime to give the PCs a chance to find the magic weapon. Realize they also should have access to things like magic missile and the spell magic weapon just for such occasions.

[The Quite-big-but-not-BIG Bad]

Or build the railroad where the train is going anyway by inserting the rooms and encounters they missed in the path they're currently taking.