I've seen First Strike, +xx% bonus against <insert unit type>, +xx% when in <insert terrain type>. Are there any others? (I'm kind of wondering if we'll be able to bring back separate attack and defense scores, by bumping up percentages on attack, for instance.)

Also, can you attack from a distance with siege weapons? I'd like to be able to fire my catapults from a distance, rather than risk them against melee units. And do they have separate bombard strengths? And can they attack terrain improvements, like in SMAC and Civ3? (I ask this here, because it's something people will hopefully be digging into.)

Siege weapons mostly have two kinds of attacks :

1/ bombard (with no danger for them) a city which (if it works) reduces the city defenses. A bit like WWI artillery smoothed the defenses/fortifications before an attack. However it has no effect on the values on the troops inside, just on their defense bonus within the city. Quite useful though, especially for larger cities with defenses and long-fortified troops. This is equivalent to strategic bombing.

2/ a standard "melee" attack. This is more tactical, just like if you moved artillery at closer range. The effects are more direct as it can hurt or even kill the unit it attack. You can also cause collateral damages to other units within the group you attack (BTW in this case the group does not need to be in a city). The main shortcoming is you can suffer damages also and can even lose your troop. But most (if not all) artillery units have a retreat capability when attacking.

and the aspect of collateral damage worked in when attcking stacks:goodjob:

2/ a standard "melee" attack. This is more tactical, just like if you moved artillery at closer range. The effects are more direct as it can hurt or even kill the unit it attack. You can also cause collateral damages to other units within the group you attack (BTW in this case the group does not need to be in a city). The main shortcoming is you can suffer damages also and can even lose your troop. But most (if not all) artillery units have a retreat capability when attacking.

I dunno... I'm not too keen on this feature. Artillery never go it alone into combat. They also never completely destroy an enemy force. They soften them up, but without infantry, your cannons become THEIR cannons. I liked the old way of capturing artillery. Does the fact that it has a combat value mean it can't be captured? That would be very disappointing.

Does the fact that it has a combat value mean it can't be captured? That would be very disappointing.

Capturing artillery would be relatively simple to mod.