Im doing a turnbased strategy game set in the near future. Similarily to "Total War"-series, the player takes command of an empire and controls cities and trains armies. The game plays out on a world map with other empires trying to dominate the world and conquer cities.

I want to include WMDs and here are some ideas I like to have feedback on! There is "research" in the form of discrete "inventions" that unlock buildings/units and/or gives bonuses. The three branches of WMD will probably have some Tech tree connected to it so an empire can focus on one but not another and so on.

All WMD will target cities, armies moving around cannot be targetd.

NUCLEAR
Deploy with missiles (from cities or from submarines)
Large damage on armies, population and buildings
Most expensive of the three.
Fallout stay and makes the city less liveable/productive?

BIOLOGICAL
Deploy with missiles (from cities) or by agents (chance of not detected who released the WMD)
Some damage on armies, large damage on population
Can spread to other cities ("plague" mechanism)
Slow, lasting effect on population decrease

CHEMICAL
Deploy like biological.
Some damage on armies, large (largest of all three?) damage on population
Cannot spread. Immidate loss of population but no lasting effect (a single turn is 3 months so no effect "after that").

What do you think of this basic ideas? Can they be made even more distinct from each other? (right now only nuclear affect buildings for example). I could also skip one of them (chemical seems the least interesting).
Thanks 
Erik

Biological agents might have diminishing returns as vaccines are developed. They're also the most dangerous for the user (virus escapes the lab, sickness spreads to your own troops) which could have either accident risk or just an internal morale hit.

Chemical weapons could be defended against (provision of gas masks to the citizenry).

You specified they could only be used on cities, but chemical weaponry in particular can be used as an "area denial" weapon.

I think the biggest questions, though, are on theme and tactics. War games are inherently violent, but chemical and biological atrocities are particularly heavy content. Does it fit in with the tone you're going for? Could it hurt marketability? How are your going to present these actions?

Tactically, they can have a major impact on how a war is fought. Is there still a role for ground troops once nukes are in play at all? If it's a free-for-all among multiple empires, does the mutual destruction action make for fun gameplay (where use of WMD beget counter-use of WMD and leave both empires weakened and easy pickings for another side)? Would the stockpiling of weapons and then a sudden carpet bombing of a player leave them unhappy with the game?

The basic idea is fine, but I think the implementation details need careful thinking.

22 hours ago, suliman said:

. I could also skip one of them (chemical seems the least interesting).

I 'm no expert on mass-genocide, but i think there 's some overlap between chemical and biological weapons, and they could be called biochemical weapons.

Also i would skip the biological/virus. Viruses give annoying questions like what happens when the player activate a svirus while there is/are still active viruses on the map, how is it going to spread, why doesnt it affect your own population etc.

BIOLOGICAL: It WILL affect your own population. Im thinking something like the plague mechanics in total war: medieval 2. Basically each city will have a desease rating which you can boost with biological attacks. Highly infected cities can spread to nearby cities, regardless of who contols them.

I disagree with the decision to not allow WMD to target forces as their strategic/tactical reality has dramatically reshaped force composition and arrangement (especially nuclear). It would be nice to see strong, slow moving forces more vulnerable than rapid force, creating a strategic trade-off (and discouraging stacks of death if you have stacking).

 If your setting is near future, rather than a straight NBC breakout, what about:

1) High yeild nuclear - Mass destruction, multi-tile weapons such as hydrogen bombs. Biggest, most difficult, most expensive to build. If diplomacy is in scope, significant penalty for building (would be nice if it harms alliances and causes AI to pay more attention to your doings).

2) Low yeild clean nuclear - Good for clearing a tile of unarmored forces, air power. AFVs, cities with bunkers less affected. Can be delivered by artillery, air power, subs, agents. Effectiveness is balanced by high upkeep / maintenance cost (vs. high research cost of high yeild).

3) Viral - Same as your biological mechanics but I'd make it possible to spread to ANY nearby cities, armies along the road (or if you have it, air) network. Long incubation time, exponential growth among empires not devoting production/wealth to maintaining the population (abstracted healthcare) and high growth among lower tech empires (if you have TL differentiation).

4) Genetic - Same as Viral without the spread as it targets a specific empire. Longest research time, highest diplomatic cost. (Atrocity mechanics of Civ/Alpha Centauri games would be perfect here, imposing possibly crippling trade / diplomacy costs). You could extend this to targeting food supply rather than population as well. I think the effectiveness would merit a Pandora's Box mechanic similar to plague spread, maybe in the form of some kind of unintended super-mutation possibility.

5) Chemical I guess could still be a low-tech tactic. It would be interesting if tiles had a notion of pollution because in the spirit of area denial mentioned previously you could cause units in an area to be damaged over time. If cities need tiles for production, this could be a way of denying tiles as well. 

Something that doesn't get included enough in these types of games is the reason why these weapons aren't simply a dominant strategy, and that is the idea of the commons. If there are blow-back effects to using some weapons, it creates a depth and tension to choosing one strategy over another. Mutually assured destruction, the idea of the risk of destroying the common environment to the point that it not only affects your enemies but you and your allies, would be a powerful balancing mechanic to WMD in an empire game. 

Another quick thought: If you have any modifiers to building / maintaining forces, it would be interesting if you could rack up some sort of penalty each and every time you deployed WMD which affected it. Say you had some notion of National Unity acting as a discount for building and maintaining troops (or build time accelerator). Each time you deploy WMD, National Unity would take a hit. This would make it more expensive to build and maintain troops (and/or slower). So you could still viably use them (as in World War 2), but your decision to do so would have to be very strategic and limited.

(Heh, you could also force players to offset this National Unity cost with other expenditures, such as Humanitarian Aid or Propaganda. You could even tie down forces over several turns on some areas of the map as they get bogged down generation National Unity via Humanitarian Missions... but that might be beyond scope) 

I think this would work better as a balancing mechanic than just high, upfront research costs (although I still agree with those, as well). This keeps WMD from being a dominant strategy and you might even say that it injects a bit of moral intelligence to subject matter that would otherwise be somewhat soulless.

Cool ideas!  Thanks!

Im not sure how much of this could fit into the scope of the game (im a lone developer). Easiest balance seems to just make them so expensive that it's only worth in very specific situations. I may include diplomatics if i can (in that case, those will defenitely be hit as well).

Terrain will not be altered, that is to advanced for me:) I like the idea with unity and countering it with propaganda! Might make it into the game somehow.

I might in that case have two empire-wide meters:

Corruption (0-100%). This lowers overall income by the % of corruption and is increased by total distance of all controlled cities to the capitol. Can be lowered by research and some buildings, or by moving capital to "center" of empire (like in civilization).

Unity (0-100%). Lowers when using impopular methods (WMD, breaking deals, population resettlements, etc) or when conquering new cities. Recovers over time or when using propaganda, some research etc. Inflates military costs (both upkeep and training new units) with 1/unity. So double costs at 50 % unity and "infinite" cost at 0 % unity (0 % unity would signify a total collapse of the empire and wouldn't really be possible to reach).

Could that make sense?