Tuesday 7 July 2015

Game Design #47: In Praise of Area of Effect (AoE) Weapons

Area of effect (or template) weapons are widely hated in most videogames.
"Skill-less"  "For Noobs" are some of the comments directed at their use.
They aren't always too popular in wargames either.  It's not fun to have a template placed over a large formation and know your fate is in the hands of the fickle, cruel dice gods.  Artillery alpha strike in Turn 1? Not fun to be on the receiving end. 

But I'd argue AoE weapons are good.  There should be more widely used.
They create terrain.  They create maneuver.  They create tactical possibilities. They create choices.

At a Basic Level
In a game like Warhammer Fantasy (where units are drawn up in prescribed regimental formations) they may merely make another differentiation between skirmish and line troops.
In a game like Lord of the Rings, where you can form up troops however you like, it forces some simple tactical choices.  Do you group up your forces to get more minis into a melee? This makes you vulnerable to AoE weapons.  Do you spread them out to avoid AoE, but potentially weaken your melee potential?   However when templates can be used in Turn 1 to wipe out units before you (or your opponent, for that matter) gets to even activate them... that's not fun.  Simply having AoE weapons exist in your game doesn't mean they add that much to the gameplay.  

Where AoE Shines - Reactions
I think AoE starts to shine when target units are allowed to react to the template before the hammer of doom smites them.  For example, you might place the template in your turn, but it only takes effect after or during an opponents' move.

Not only does it remove the impotent frustration of "great, I'm about to be smashed by a template on Turn 1" but it adds some interesting tactics. You might place templates to funnel enemies in particular direction or deny them an area of the tabletop. Enemies may even decide it is better, tactically, to move through/remain in the AoE zone.  Lots of choices, in addition to the differentiation and formation choices I already mentioned.

Basically, the AoE weapon template becomes interactive terrain.  

In Warmachine, one of the autocannon-equipped steam robots has a series of linked blast templates which are laid on the board. It then acts as a kind of "overwatch"in the enemies' turn - enemies enter the AoE zone at their peril.  It can create "no go" zones to protect friendlies from attack or interdict the path of enemies. 

In FFTW3, artillery templates can be "moved" (corrected) short distances allowing them to zero in on slow moving units.   Infantry on foot need to move quickly to cover or risk being decimated.

In my Delta Vector homebrew space game, I viewed AoE weapons as an answer to add "terrain" and interest to the rather featureless void; all missiles act as AoE weapons, attacking any ships moving through their (predictable) engagement zone.  As ships (also using vector movement) are also predictable, it means ships at slower velocities may more easily use thrust avoid the engagement zone.  Since high thrust allows you to position your ship better to both launch and avoid missiles, it adds value to high-thrust ships as missile boats and escorts.

In DvTG, missiles work as AoE, and attack enemies moving into/through the AoE radius.  High thrust (+ low velocity) allows you to more accurately place your missile template or evade enemy templates.  High velocity gives your missiles more range. 

AoE in Modern Games
As I've been reading a fair bit lately about WW2 battles, I've noticed how most often, fire is directed at a particular terrain feature ("the house on the left"  "the length of a hedgerow") rather than specific targets.

Most times when specific enemies/units are targeted there are
(a) very few targets - i.e. small machine gun crew
(b) there is little/no return fire - i.e. fleeing/surprised enemies
(c) the target is point blank/urban (~50m max).

When I read about battle accounts, much of the description is auditory. It talks about the noise, and "volume of fire."  It seems most small arms fire is suppressive in nature. I recall it was estimated ~10,000 rounds were fired per kill in WW2.  In-depth studies after the war showed only ~15% of soldiers aimed to kill anyone.  Even in the air war, 1% of pilots accounted for 30-40% of the kills. Most accounts by combat soldiers highlight the times they fired on specific enemies (or even clearly saw enemies) as unique, isolated incidents.

AoE weapons did most of the work - artillery/mortars accounted for the majority of US and Germany casualties in the ETO.  I'd argue most automatic weapons can be classed (and were used as) AoE weapons as were, in general, the rifle fire of complete squads and fire teams. 

"Pushed them back"  "Pinned them down"  "Kept their heads down" are terms more commonly used then "killed lots of them"- the latter is used more often in conjunction with the results of artillery/aerial attacks.

Area Fire though tends to be more an optional rule in many wargames. You get a choice like: Do you shoot normally or try to "suppress them" with a special "suppression fire"  rule?
 I'd argue that "suppressive" area fire is the norm and aiming at specific targets is unusual unless under specific circumstances.  What we call "normal firing" (shoot to kill at small groups/individuals) would be reserved for specific roles, circumstances and individuals (either by training or temperament).  

Q: Should area fire in modern game be the "norm" for infantry units rather than an optional/extra rule? 

Another thought, is how quickly does it take a (squad+  size) unit to "cease fire"  - maybe area fire must continue for 2 turns before you can switch targets?

Quick Rant: It amuses me when the "Suppressive Fire" rule sounds something like this:
Suppressive Fire Rule:  Cannot do damage, but add extra "pin markers".  
I always imagine the squad leader saying "OK guys, switch magazines to nonlethal nerf rounds - that'll scare them!"
Bunching Up - Morale & AoE
I've mentioned this briefly in another post, but apart from not using cover well, something the veteran soldiers hated about newbies was their tendency to "bunch up" and attract fire from AoE weapons like artillery or machine guns. 

It would be interesting to see this as part of morale rules - a failed morale roll would see minis move closer together (touching bases?) making them an easier target for AoE weapons.  

A quick recap:
*AoE can be used to differentiate between troop types and allow tactical choices
*AoE can give choices (good) especially if you allow targets to react to it
*AoE can act like interactive terrain
*Should AoE be the "norm" in all modern (WW2+) games?
*AoE rules - can we link them to morale and unit cohesion?

Oh, and a quick rant.  I hate, hate, hate "guess the range" AoE template weapons.  Yes, that adds a "skill" but it's a skill a historical commander didn't have.  Artillery accuracy should depend on the troop skill level of the gunners operating them, (abstracted in the same may all other unit fire is done - by modifiers and dice rolls) not the precise estimation skills of the supreme commander of guessing ranges under 6 feet on a table.  Even if we (somehow) convince ourselves this is valid, if we go that route we may as well guess the ranges for every rifle shot fired from each and every mini.  It's nonsense, no matter which way you slice it.

Remember, if you like the Game Design articles, there are more here.  A lot more.   


  1. Another great article, I'll take sometime to digest all that you have written here :)

  2. The original Warzone and Vor both had options to dive out of the way of incoming shells, provided you had reserved actions.

    As an aside, when I did Clash on the Fringe, almost all weapons use a template of some sort (almost).
    Means if you want to bunch up, you gotta want it bad enough or you get shredded.

  3. "The original Warzone and Vor both had options to dive out of the way of incoming shells, provided you had reserved actions"

    It's amazing how so many old games had stuff we have somehow "lost" in the intervening years. Some of it is to make the game appeal to the lowest common denominator. I sometimes think that "friction" elements that stop the player doing exactly whatever he wants in his turn are also unpopular. I wonder if PC games have accustomed us to "godmode".

    "As an aside, when I did Clash on the Fringe, almost all weapons use a template of some sort (almost)."

    I noticed that in the beta copy. Another game that does it is Battlefield:Evolution, by Andy Chambers of all people.
    I think we've already discussed the grouping-coherency-detaching troops-AoE factors which seem linked (also linked with morale)?

  4. Yeah, AoE weapons and suppression fire should probably play a larger part in most games then they normally do, and the "morale-failure causes troops to group-up" idea is quite interesting.

    One note though: when I was reading a regimental history of one of the Australian units from the Vietnam war (I think it was the 8RAR) the author pointed out that the ~10,000 rounds per a kill stat from the Vietnam war is probably technically accurate [for the US military], but is not reflective of fire by infantry weapons because it includes shots fired by helicopter mounted miniguns (mostly used as an area denial weapon) and during the "mad minute" (basically everyone empties their mag into the forest when the first wake up, and before going to bed), and it also only counts the confirmed kills (a lot of Vietcong would have only been wounded and forced to retreat, or had their bodies removed by friendly troops).

    The Australian regiment in question didn't have miniguns, and didn't practice the mad minute, and they where seeing numbers of around a few hundred per-confirmed kill, and the soldiers in question believed that they where actually causing significantly more casualties than where "confirmed".

    The general point still stands of course even if it's only 90% [adjusted for misses] of rounds being used for suppression rather than 99.9%.

    1. The question is - "Was the vast majority of infantry fire suppressive fire, aimed at area features rather than specific enemy combatants?" I believe the answer is yes, it was.

      As to exact numbers, they vary wildly.

      I believe the numbers bandied around are something like Vietnam was ~50K rounds per kill. Iraq etc is 120-250K - depending on your source. WW2 was much lower (due to bolt action rifles etc and lack of gatling weapons).

      I've heard numbers like 80 per kill in Falklands (infantry small arms), but only 1.3 or so for snipers. Again, I can't recall the sources so take this with a pinch of salt. I've heard 1:100 from Vietnam, and 1:33 for the Aussies (Aussie source, so perhaps biased!)

      However, its rather tough to make sense of the numbers, taking the stats without any context.

      Its like Nevada has seen hundreds of nuclear explosions, but no one has been killed. The obvious assumption is nuclear weapons don't kill people any more, and WW2 nukes were more effective....

      That said, I don't find the large numbers startling. Think of the amount of paintball rounds fired per hit - and that is murderously point blank range, in a low pressure situation with no risk of death to self or friends, where people expose themselves willingly.

  5. The one rule that stood out to me from Mantic's Deadzone game is that if you shoot at a model in cover it is much more likely to be suppressed than if you shoot at one in the open. This flies in the face of what is normal in gaming rules, but strikes me as dead on accurate and also a nice game feature.

    Infantry tactics are about fire and maneuver. The fire is to suppress the enemy enough to allow another part of your unit to maneuver in close to them. If you kill someone great, but it's just luck, because you can't see anyone. In modern combat, if you are seen, you are dead.

    1. I've been reading quite a few Stephen Ambrose books (of Band of Brothers fame) which are full of first-hand accounts. I was surprised how often soldiers said the only German infantry they ever saw were surrendering/POWs, or in unique, isolated incidents. And these are troops who were continuously in action from D-Day to Berlin.

      The "bunch up when suppressed" rule was interesting. On a chapter on new recruits, I remember a few key reasons rookies were disliked were
      (a) inability to use cover/concealment
      (b) tendency to bunch up and attract AoE weapons like mortars/MG42s
      (c) freeze under fire/not move forward when exposed in open to AoE

      In house to house fighting, the veteran units didn't move along streets but tunneled through walls. Veteran units usually "dug in" faster and more thoroughly.

      However all units had how to "fire and maneuver" drilled into them; part of platoon establishes a "base of fire" and the rest flanked. Hedgerows made this hard in Normandy - where was the flank, exactly?

  6. Fantastic post, but think about the scale of most game boards. If a modern game or any game using modern-ish firearms as common equipment, they can reach all the way across the board (sorry, WH40K). Likewise, the deviation of any artillery round, which should be used as an off-board asset, will likely encompass more than the dimensions of the game board. I love the concepts you describe, but in most scales, they wouldn't realistically present themselves. I incorporate artillery in Force on Force games with a radius of deviation that makes them potentially dangerous to most everyone on he board, and have seen calling artillery as a decisive factor in the loss of the calling party.

    1. Sure. But we are now heading into a discussion of ground and time scale. Something many(most?) games treat as flexible. For example, in FoF, how far is a 8" move? What period of time does a turn represent?

      Without absolutes, it becomes a personal decision of what is and isn't realistic. Since I recall arty working OK in FoF without deviating the entire board, I presume wide deviation is a house rule you have decided - whereas the devs decided it was within the parameters they (rightly or wrongly) gave themselves.

      I mean, how big are the AoE templates are we talking about? Is a grenade a 1" radius blast or a 5" radius blast? How much frontage could a squad or MG suppress? (Quite a large area, judging from WW2 accounts).

      I personally think limiting rifles (40K style) to 24" is stupid, but if 24" = 300m, then it's quite plausible to make that the "effective range."

      I think I posted on scale somewhere in this series, way back at the start....

    2. No disagreement, and this is one of the most enjoyable blog series I've ever seen. As for 24" range rifles, yes - If that's 300 meters. Since it's maybe 50 or so at scale, it's insulting. Probably my biggest pet peeve in gaming. I don't demand absolute realism, but that's ridiculous.

  7. AoE weapons also provide an interesting challenge to a player in how to employ them effectively. Consider the relatively simple MG. This should generate a cigar shaped 'beaten zone' AoE. It is, therefore, best used from the flank where it can catch as many enemy in the beaten zone, not firing directly out. Getting a MG on each flank where they can generate crossfires with overlapping beaten zones - that is an art with very deadly effects. I don't think many games do this well at all.

  8. "AoE weapons also provide an interesting challenge to a player in how to employ them effectively."


    I originally disliked template weapons, as they seem a bit of a "dumb" weapon. But they offer interesting choices when properly implemented.

    And I think there is considerable evidence that AoE is more widespread IRL than in games. For example, even English longbowmen firing showers of arrows at range could be considered more an "area denial" or "suppressive" weapon. I don't see many medieval games treating them as such.

    1. Thats an interesting aspect I hadn't considered before. One could also see room for a morale test to enter such an AoE too. Charging Knights on horseback might pass, but it less likely the supporting, less well armoured peasants would... Thus the bows would really break up enemy formations

    2. Isn't that my they had knight dismount and advance on foot? i.e. showers of arrows that could maim a horse (throwing rider) at range could be slogged through on foot if well-armoured. (and if you had the guts for it, hence - AoE/morale)

      The bodkin-tipped longbow only punched through armour at ~30m or less, right?

      Random Fact: I think I recall reading recently that modern tests showed leather "jack" armour is quite effective (better than chainmail) at distributing the force of arrows; at longer ranges, also to non-lethal levels.

    3. Havoc does this remarkably well, IMO. Archer volleys hit every model in the unit (where unit is defined as all models in base to base contact). So unless you want mass casualties you either move or break formation (or put a shield wall up). It very much creates a "You need to take care of this NOW" effect -- which is what you want with artillery.

  9. the 'storm of arrows' effect was rather lethal at range also because of the plunging effect and the less armoured areas they struck.

    Its a interesting and different approach to gaming though. I can see a mechanic where an infantry squad comes under fire in an AoE (say a MG), may or may not take casualties, takes a morale test and goes to ground to seek better cover. An officer/Senior NCO moves up to rally them and push forward, but the AoE 'effect' remains until repositioned on another target or the MG position is itself silenced.

    Put that way, its seems rather simple and straightforward. Interesting that we haven't seen it in any rules to date (that I am aware of)

  10. Starship Troopers, first edition by Andy Chambers, resolved shooting almost entirely on an AoE basis.

    1. See 3rd comment down. That's the problem when the replies have more interesting content than the posts!

      This really needs to be a forum rather than a blog...

    2. Probably better as a blog - my fault for trying to skim the material.

    3. Better as both? Would love to see a forum about game design. And then each blog post could have a "to discuss this post" link? Because the blog posts are really doing a great job of guiding the discussion.

  11. You know, your pictured DvTE AoE approach for missiles would also work very well for captor mines or slow speed, seeking torpedoes in SF SubWar...

    1. True. I've tried to avoid using similar mechanics (something that peeves me off about the 'copy-and-paste' PDF rules series you see a lot of atm) but I do like the "missiles as AoE" idea - allows you to dodge them if you are fast enough.

      That said, underwater thermal vents, kelp forests, thermoclines, and giant squid will provide some terrain...

    2. Yes, overly repetitive mechanics get dull.

      But maybe the Giant Squid's tentacles can generate an AoE... :-)

  12. Speaking of resolving every bullet from every model, I made a game years and years ago that did something like that, where the players marked out the trajectories of the shots using string. Perhaps for obvious reasons it didn't catch on.

  13. "I hate, hate, hate "guess the range" AoE template weapons"
    +1. No, make that + several million. I recently hit this with cannon in Havoc, but I don't see an easy way to replace it. A catapult could use a scatter die, but that didn't feel right for a more line of sight weapon like a cannon or a ballista. I'm still trying to figure out how to replace this.

    1. I'd not use scatter, but use a normal to hit roll.

      If it misses, mentally make a line between the target and the firer (that extends infinitely in either direction).

      If any units (friend or foe) are along this line, roll "to hit" against the closest, with say only a very small chance to hit (i.e. 1 on d6).

      After all, scatter is meaningless unless it hits something.

      Firer----------------------------> target --------------> other unit, in line of fire, who may get hit by a shot that misses the original target...

    2. I you want to get real old school, make a template to place over the target along that line, with numbers showing where the fall of shot goes. Make those closest to the target in either direction high numbers and those farthest away low numbers. Roll a die to see where the round falls. Add 1 to the die roll for every subsequent turn you miss to show the rounds being 'walked' onto the target.

    3. A system I like (though probably not suitable for your purpose) is the FFTW3 arty rules.

      You place an arty template over your target in your turn, but nothing happens (firing an ineffective ranging shot)

      AFTER their turn (giving them time to move) the fire from the whole battery hits and everything which is still under it is hit.

      In your turn, you may move the template a few inches (correcting the shots) which can be outrun by vehicles or infantry fleeing hastily.

      It makes artillery good at zeroing in on entrenched/static positions but unlikely to hit moving units who can flee the barrage. It makes it a good area denial weapon. It's also very simple with no deviation rolls etc.

  14. @Paul - I like this idea, and was thinking about using something similar with the scatter dice. On the 6, you hit. On an arrow it scatters back or forward in the direction indicated, but only along the line of fire.

    @evilMonkeigh - The FFTW3 rules are similar to Stargrunt and Dirtside and work well in those systems. I like the affect of zeroing in with spotting rounds and the area denial effect. But as you say, not really the right effect for ballista and early cannon.

    So I think I will incorporate two suggestions for my next game of Havoc. One is a to-hit roll. For this I will need to think a bit, because I can't remember if artillery crew even have a ranged attack value. But if not, I think I can assign one fairly easily. (And that leads to the idea of having "elite" crewmen who have, say, a 1 higher ranged attack value. I like that idea.) And if they miss, then roll a die to see if they are over or under (even or odd) and then another die to determine by how much.

    Finally, if needed, use the normal "bounce" rolls (in Havoc, if you don't hit your target the cannonball may bounce along the ground. This doesn't make as much sense with a ballista bolt as with a cannonball but it's how Havoc handles it).

    Great discussion - thanks!

  15. Excellent book "Shots Fired in Anger" by John B. George, has a chapter describing a battle between U.S. Merrill's Marauders and Japanse army troops in Burma. The Japanese pnned down the U.S. troops with intense small arms fire, the soldiers could not move from their foxholes or return fire. It was expected that the Japanese would send units around the flank and once they were at point blank range the pinning fire would stop and the Japanese would overrun the Americans. An excellent example of AoE fire, the Americans were not taking casualties but they could not move or prevent the Japanese from closing. Instead of flanking the Japanese lifted their fire and charged the Americans who were on the other side of a small river. The Americans being no longer pinned down were able to use accurate aimed fire at the Japanese. The American fire did not pin down or drive off the Japanese, it killed them. John describes that a few Japanese made it across the river before being killed with most of them falling in the river. This then becomes an example of the use of aimed fire at enemy troops without cover.

    1. Thanks - that's a great example of what I'm trying to say.

      Suppressive fire is the norm when fire is being exchanged; then aimed fire for particular circumstances....