Couple Questions I need Clarified

Spell Mastery is "Accuracy for Mages", opposed to Spell Resistance instead of Dodge. Basically it allows your spells to land instead of getting resisted and its value is the 'to hit' of the spell minus SR.

Influence is a sort of resource which can be used in trade and for a few other reasons, but they aren't many. It pretty much represents your political clout. There are several ways to obtain it, although not all of them will be available at any time. Constructing non-city monuments (i.e. those resources you see on the map) nets you +1 Influence per turn. Completing a quest as Altar (or anyone with the Heroic faction trait) will net you +50 Influence per quest. Legacy of Serrene faction trait will grant you Influence per completed caravan. The Missionary faction-unique building, like monuments, gives +1 Influence per season. Then you also have the option to trade for it, just as any other resource. I may be forgetting other sources besides the occasional quest-reward (specific to the quest as an option, and stacks with Heroic).

Thanks for the info.

Although I had a couple hundred points of political capital and I couldn't build it.  I had the over requirements including the over three structures.  The Forge only required -3 influence to build it.  Unless that is a typo.

I had my own experience with this,  where I had over 300 influence and still couldn't build it.  The problem sometimes is that if you need more crystal, the popup will still say not enough influence.  So watch out for this phenomenon. 

Again, thanks for the info