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A better reaction fire system

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Anton:
Hi all, you may find the following of interest...
Questions are welcome, though I am not sure someone ever reads this huge post...
//And sorry for my English

A System of a Tactical Turn-Based Game

Well, it's well known that turn-based games are great. The division of the in-game process into alternating turns, cyclically performed by the players, gave, first of all, the ability to play games requiring the player to control a complex system of interacting objects without hurry, allowing him to carefully analyze the situation before making any actions.

Second, the turn based system naturally  allows for comfortable play of more than 1 players on the same machine, which is not used by many modern turn-based games for some reason.  

And the main drawback is called turn-based-ness. When one player is active the other is waiting for his turn. In turn based tactics it yields unnaturally uneven gameplay, where the same situation can lead to totally different results if occurred in different turns, and even at different moments of a turn.

To partially compensate for this effect was developed the so called reaction fire. The units could act (often only make a limited number of shots) in the opponent's turn in reaction to certain events, mostly - spotting an enemy. In spite of the high non-symmetry of such system, in some games (X-COM 1,2) reaction fire occurred not every time it could happen, only part of possible reactions were realized. The chance for a given reaction (or opportunity) fire to happen was hard-coded or depended on the unit's reaction. This was an additional non-symmetry because in active phase units surely made a shot if
they'd been ordered to.

Also, reaction fire often used action points reserved from the active turn, so if someone was moving at his maximum speed, he couldn't react at all, which's ridiculous too.

So I decided to propose a better reaction fire system, which, being within the general frame of XCOM-like system, would be less prone to the indicated (and maybe some other) drawbacks.

First notes

Here I am based entirely on the following statement. Since turns are just a logical division of time, ideally, the outcome of any situation mustn't depend on in which turn it occurred and at what moment since the beginning of the turn.

First, my system has one global distinction from the XCOM-like RF-system: it doesn't feature saving time units for reaction. The reason's quite evident.

Let's consider the following situation from viewpoint of the XCOM-system. Unit A has taken position in a shed, taken aim at the entrance and saved say 24 time units for a snapshot. Then, an unwary unit B from the other team tries to enter through the door and... gets spotted by A.

In XCOM A will be given a chance to react, depending on A's reaction. The chance may also depend on the type of shot, B's reaction... - I don't know exactly. Anyway, once the chance is calculated, computer generates a random number and decides whether A can conduct reaction fire or not. If A is lucky, he'll make shot and kill B. Suppose, his snapshot costs 22 TUs, so A can't shot during the opponent's turn anymore. Thus, if enemy C sneaks along the wall and then rushes into the shed, A won't do anything. A has spent his TUs and now he can only stay motionless and watch C killing him.

Now, let's imagine the same situation with the only difference: at the beginning of his turn, A was closer to the shed, so when he entered it and turned around to face the entrance, there were 44 TUs at his disposal. Again, if he's quite lucky, he will kill B and still keep one reaction shot on hand. Now, C won't kill A so easy, because A will try to react for a second time (22+22=44)

But wait, the above two situations are different only within the XCOM turn-based system. In reality they'd be identical: A hides in the shed, B and C pursuit him, entering the shed one after another. And since our purpose is to make a more realistic turn-based system, here goes the first distinction:

In my system time units will not be saved for reaction. A unit will be able to react throughout all the opponent's turn irregardless of how many TU's he's spent in his preceding turn. And this is based on mere evidence: in real battle nobody stays quietly under fire because he's run out of his time units.

Thus, in my system units receive the same amount of TUs in the beginning of each turn, irregardless of whether it is their or the opponent's turn.

Another problem with that feature of XCOM system: the faster you move during your turn, the less TUs you have to react in the opponent's turn, and vice versa. Thus, if you run as fast as you can, you may be sure that if an enemy spots you in his turn, you won't be able to walk a couple steps or make a shot, how realistic! As you see, in XCOM the outcome highly depends on the way time is divided into turns and on the location of the moment on the time axis relative to the boundaries of the current turn.

Note, that the above proposal reduces this dependence: whenever reaction occurs, the unit will react the same way. Ok, we are moving in the right direction.

Now, another connected problem: in XCOM any action (a shot, for example) was located within one turn. You weren't able to start shooting in your turn and end in the next opponent's turn. This led to a ridiculous situation: if you had 23 TUs and your snapshot costed 24 TUs, you couldn't make a shot. 1 TU significantly effected the outcome, which, of course, is incorrect. So, the second rule reads:

New turn doesn't cancel actions started in the previous turn. Thus, however few TUs you have, you may spent them on anything you want. In this case your orders will be complete in the enemy's turn, and vice versa: unfinished reaction fire (or other reactions) will be accomplished in your next turn, if you don't cancel them.

All actions are performed at the expense of TUs the unit's been given for the current turn, so this "interturn" action spend the last TUs of one turn and the first TU's of the next one.

For example, you have 8 TUs and give a snap shot order, costing 20 TUs. In this case 8 TU's will be spent in your current turn, and, in the opponents turn, your unit'll spent the resting 12 TUs and take the shot.

This will make interturn transitions smoother and more realistic, because in reality there are no turns and no interturn boundaries.

But the opponent (in his turn) may escape your unit's LOS before he shoots. Yes, and in this case your unit shouldn't shoot. But TUs spent on aiming won't be reset. Your unit'll just stop aiming.

For example, in the opponent's turn you spent 10 TUs before you lost the enemy. But you needed 2 TUs more to shoot. In this case you don't shoot and your total TUs (for this turn) are decremented by 10.

Now you should have understood that in my system both your and the enemy's units can act simultaneously. Yes, it is true. And the turn defines only who can control his units (active turn) and can't (passive turn). The units of the latter player are controlled by their reaction instructions or they are finishing interturn actions.

N.B.: Reaction instructions are ones that define a unit's behavior during the opponent's turn. They are defined by players in their active turns. In case of interturn actions there are two choices:
1. Reaction first - when the interturn action is interrupted if reaction condition occurs.
2. Interturn action first - when the unit finishes his interturn action and only after that becomes ready to react.

Now, it's time to discuss the structure of the in-game time. We have simultaneous actions performed by both the sides (In XCOM the inactive side could perform only momentary action - reaction fire, which wasn't considered as having length), so there should be common time counter for the units of both teams.

Current time in my system is defined as the maximum number of TUs spent by the units of the active team.

Thus, all interturn actions of the passive team are synchronized with this parameter. Such structure allows for real simultaneity: for any given moment both teams have been acting for the same period of time.

Reactions will use a similar synchronization as well, but with a little modification. When a reaction begins (reaction condition's just been met), a snapshot of the active team is made: for each of the active team units their spent TUs are remembered S1,...Sn. T-parameter, time spent by the active team from the reacting unit's viewpoint, will now equal to the maximum of times spent by the active units since the "moment" of the snapshot (as the active units continue to act after the beginning of the reaction):
T=max{S'1-S1,...S'n-Sn}, where
S'i denotes TUs currently spent by the i-th unit of the active team (changes with time), while Si is the same value measured at the moment of the snapshot (it is constant for the given reaction).

EXAMPLE OF REACTION FIRE

Active team - A, it's units are A1, A2 and A3
Passive team - B, the units being B1 and B2

A2 goes into a shed (spends 24TUs), A1 turns round the corner and (spends 36 TUs) gets spotted by B1. (A3 hasn't moved) It takes B1 16 TUs to shoot. Now reaction will happen when:
[The snapshot in this situation is {36, 24, 0}]
1. The reacting unit is alive and has kept A1 in view since he saw him.
2. Unit A1 spends 36+16=52 TUs or A2 spends 24+16=40 TUs or A3 spends 0+16=16 TUs.

Once these conditions are met, the reaction is performed immediately.

Thus, not only A1, but also any his teammate will cause reaction by spending  more than 16 TUs since the snapshot moment.

Also it may happen that B1 loses sight of the target before he can shoot. In this case the reaction doesn't occur.

Irregardless of whether the reaction took place or not, the unit stays able to react over the whole enemy's turn. But, of course, that doesn't imply he will fire at any incoming enemy. First, his reaction time may be too high (and the enemy will shoot him first). Second, he may be attacked by several units simultaneously (and, of course, he won't have time to make a shot at each of them). note, that in UFO the were no way to use simultaneity this way.

In my system it makes difference: whether a unit was attacked by several enemies at once or sequentially, which is also a serious improvement to realism compared to the XCOM-like RF-system.

How it looks in active turn:

Suppose you've encountered an enemy unit that is executing an interturn action - running to behind a tree. You give a snaphot order to your unit. In X-COM you unit would take a shot immediately on reception of the oreder. In my system nothing happens except the order is attached to the unit. That is, your unit has just starting to aim at the running enemy.

Now you can switch to other units. As the time spent by your team increases, the unit will take aim and shoot, unless the target kills him or escapes his viewfield before he has time to perform the shoot order.

... to be continued.

Bandobras:

--- Quote from: "Anton" ---Questions are welcome, though I am not sure someone ever reads this huge post...

--- End quote ---


I did. :) Nice reading.

First comment --- I think turn-based is great, because the fact that I cannot react (apart of reaction fire) in my opponent's turn nicely models the effect of initiative and of surprise. In reality I do just that --- I leapfrog, I perform order after order to move somewhere and then shoot, etc. I move and decide in phases and I cannot change the plan immediately if I see somewhat unexpected. The opponents turn, during which I'm unable to move, models the time it takes for me to prepare for the next leapfrog, to change my plans (perhaps consulting my superiors, too). The unreliable reaction fire models my unreliable instinctive reactions, before I made a proper plan-change (in my next turn).


--- Quote ---First, my system has one global distinction from the XCOM-like RF-system: it doesn't feature saving time units for reaction.
--- End quote ---


Saving turns is realistic. If I choose a proper spot, stand still, aim my gun, scan sourroundings, I'm more likely to react, but it all takes time...


--- Quote ---In XCOM A will be given a chance to react, depending on A's reaction. The chance may also depend on the type of shot, B's reaction... - I don't know exactly.
--- End quote ---


IIRC in XCOM it also depended on the movement points left (after the shot, IIRC) both for A and B.


--- Quote ---But wait, the above two situations are different only within the XCOM turn-based system. In reality they'd be identical: A hides in the shed, B and C pursuit him, entering the shed one after another.
--- End quote ---


I'm not sure. If A is caught in the middle of the shed, with his back to one of the windows, with his gun down and not even a clear idea if there are other exits and where to aim if a noise is heard from behind, he will be killed by C. On the other had if he is well-prepared for the reaction shot he will kill C.


--- Quote ---In my system time units will not be saved for reaction. A unit will be able to react throughout all the opponent's turn irregardless of how many TU's he's spent in his preceding turn.
--- End quote ---


Regardless of what I said, this sounds interesting, though I'm not sure if this does not encourage camping (normal reaction fire mechanism somewhat encourages it, too, BTW, so I'm not that fond of it). Once you reach a nice camping spot you can defend it with all power. In XCOM your opponent could at least attack you for free during the first turn. This encouraged slower tactical progress instead of a race to the best camping spot. However, all tactical implications of your proposal may be more complex and perhaps even generally good --- I don't know.


--- Quote ---And this is based on mere evidence: in real battle nobody stays quietly under fire because he's run out of his time units.
--- End quote ---


If somebody is not prepared he will take more time for his shots, possibly even stumble or duck and indeed stay quietly until he analyzes his situation (until his next turn).


--- Quote ---Thus, if you run as fast as you can, you may be sure that if an enemy spots you in his turn, you won't be able to walk a couple steps or make a shot, how realistic! As you see, in XCOM the outcome highly depends on the way time is divided into turns and on the location of the moment on the time axis relative to the boundaries of the current turn.
--- End quote ---


Yes, this is the model, and I think it works OK. Just imagine that every turn you perform an order, a plan of action. Then, during the opponent's turn you syncronize through radio with your buddies, receive/plan next orders, etc. With this view, if you have wrong plans/orders that leave you exposed and exhausted in the middle of the field, while you are briefed for the next step, this is entirely your (or your superior's) fault and a very realistic fault, too. Professionals do not run continuosly ahead, shouting and firing. They leapfrog, stand still, and leapfrom again...


--- Quote ---This will make interturn transitions smoother and more realistic, because in reality there are no turns and no interturn boundaries.
--- End quote ---


Just think about half of your movement points as belonging to the opponent's turn. Then the current system is very close to waht you describe. :) Once you have the habit of reserving points for the reaction shots, it really plays more smoothly and most of you reported problems are solved (e.g. you suddenly end up close to an opponent --- just sacrifise some of the reaction fire points to flee or to kill him outright).


--- Quote ---First, his reaction time may be too high (and the enemy will shoot him first).
--- End quote ---


A nice idea. It is, to an extent, modeled by the impact of remaining TU's of both units for reaction shots in XCOM.


--- Quote ---As the time spent by your team increases, the unit will take aim and shoot, unless the target kills him or escapes his viewfield before he has time to perform the shoot order.
--- End quote ---


This does not sound very realistic. This is a duel and your soldier is handicapped by the rest of his team. Do I get it right?

Anton:
Sorry for misprints and English, I passed an exam today and have another one the day after tomorrow — not enough time.


--- Quote ---First comment --- I think turn-based is great, because the fact that I cannot react (apart of reaction fire) in my opponent's turn nicely models the effect of initiative and of surprise.
--- End quote ---


I think turn-based is greate because it allows for hot-seat multiplayer...


--- Quote ---In reality I do just that --- I leapfrog, I perform order after order to move somewhere and then shoot, etc. I move and decide in phases and I cannot change the plan immediately if I see somewhat unexpected. The opponents turn, during which I'm unable to move, models the time it takes for me to prepare for the next leapfrog, to change my plans (perhaps consulting my superiors, too). The unreliable reaction fire models my unreliable instinctive reactions, before I made a proper plan-change (in my next turn).
--- End quote ---


Huh. Ok, in reality that leapfrog tactics is used in areas with dense relief, where you have a lot of covers like cars, buildings, and so on, and inside buildings, of course.

But I see some problems:

First, while in reality this leapfrog technique emerges naturally, in your interpretation of the XCOM system it is fixed. The players are forced to use this technique.

Second, in the XCOM system these rushes are made by the two teams in turns: first, one team makes a rush, then the second and so on. That is, while one team is making a rush, the units of the second stand still, and vice versa. But in reality leapfrogs are not made in this way: every unit makes rushes more or less asynchroniously with his teammates, at least with the ones located quite far from him. And of course, the leapfrogs of the two teams are in no way turn-by-turn: the enemy will rarely wait for you to make your umpteenth leapfrog before making his.


--- Quote ---Saving turns is realistic. If I choose a proper spot, stand still, aim my gun, scan sourroundings, I'm more likely to react, but it all takes time...
--- End quote ---


If you are sneaking along a wall and know that round the corner has lain doggo an enemy, you are very well prepared to react, maybe faster than the enemy, not aware of your approaching. And it in no way depends of the TUs you will have when turning round the corner.


--- Quote ---IIRC in XCOM it also depended on the movement points left (after the shot, IIRC) both for A and B.
--- End quote ---


Yeah, that's pretty strange. If you meet an enemy in the end of your turn, in the middle of it, or in the beginning — why should you have different chances of shooting first? The situation is the same except the moment it occured. Or do you think if you leave 40 TU's for reaction, you will spend them all to "prepare to the shot", though you don't see an enemy and even don't know if one appears. Reaction starts at the moment you spot the enemy!


--- Quote ---I'm not sure. If A is caught in the middle of the shed, with his back to one of the windows, with his gun down and not even a clear idea if there are other exits and where to aim if a noise is heard from behind, he will be killed by C. On the other had if he is well-prepared for the reaction shot he will kill C.
--- End quote ---


But the difference in the two situations was only one: in the TUs reserved by A, the other conditions the same (position of A at the end of his turn, and positions of B and C at the beginning of theirs). So, what you wrote is true but has nothing to do with my example.


--- Quote ---Regardless of what I said, this sounds interesting, though I'm not sure if this does not encourage camping (normal reaction fire mechanism somewhat encourages it, too, BTW, so I'm not that fond of it). Once you reach a nice camping spot you can defend it with all power. In XCOM your opponent could at least attack you for free during the first turn. This encouraged slower tactical progress instead of a race to the best camping spot. However, all tactical implications of your proposal may be more complex and perhaps even generally good --- I don't know.
--- End quote ---


No one-sided attacks in my system: it's not chess. Since in XCOM reaction fire is much ehhh... weaker (happens much more rarely, I'd say reaction/action shots count about 1/3 or less), it does make passive tactics less effective.

In reality it is passive tactics that gives the defender certain advantages. That's well-known that on average the defender suffer less losses than the attacker. So, my system is more realistic from this viewpoint.

You may say it'll spoil the gameplay. I think that's not true. In every real combat there is a defender and an attacker. If you shoot a small UFO down and send a Ranger to the site, the aliens will probably prefer defence rather than attack, unless they plan to break through your forces and run away and hide...


--- Quote ---If somebody is not prepared he will take more time for his shots, possibly even stumble or duck and indeed stay quietly until he analyzes his situation (until his next turn).
--- End quote ---


A unit's ability to react/act depends only on his abilities and the real situation, but in no way on whose turn it is. Turns are just logical and artifial division of time: like splitting text into several books doesn't change the text.


--- Quote ---Yes, this is the model, and I think it works OK. Just imagine that every turn you perform an order, a plan of action. Then, during the opponent's turn you syncronize through radio with your buddies, receive/plan next orders, etc. With this view, if you have wrong plans/orders that leave you exposed and exhausted in the middle of the field, while you are briefed for the next step, this is entirely your (or your superior's) fault and a very realistic fault, too. Professionals do not run continuosly ahead, shouting and firing. They leapfrog, stand still, and leapfrom again...
--- End quote ---


Maybe it works OK, but I am sure a more realistic combat simulation will be much more interesting (or at least another good game system) than this half-chess system.

Email XCOM has a really poor reaction fire system as concerns realism, but it is this system that makes an interesting game allowing for PBEM, one game taking 15-25 turns. But I think it's really strange that so far no turn-based multiplayer (not Aftermath!) games without chess-ness have been created. Synchronious move hadling (like in freeware General 4.5e) is not useble in the XCOM genre.


--- Quote ---Just think about half of your movement points as belonging to the opponent's turn. Then the current system is very close to waht you describe.
--- End quote ---


No, reread the examples. The X-COM system is extremely unrelistic.


--- Quote ---A nice idea. It is, to an extent, modeled by the impact of remaining TU's of both units for reaction shots in XCOM.
--- End quote ---


Remaining TUs, depending on the division of time, can in no way be used for this purpose. If you don't move in you turn, why will you have better reaction chances than in the case you walk five steps forward and backward? This doesn't change the actual situation, but affects your TUs... Anyway, reaction starts after spotting an enemy, not at the beginning of your turn. So, the spent TUs can not be cosidered as stolen time to prepare.


--- Quote ---This does not sound very realistic. This is a duel and your soldier is handicapped by the rest of his team. Do I get it right?
--- End quote ---


Yeah, since the enemy's actions are sychronized with the time as well, they (the duelants) are acting (aiming and shooting) really simultaneously — quite realistic.

Bandobras:
Oh, well, at least you know I've read your post, even if I have not understood. :)

About turn-based again, of course the crucial thing for me is that I don't have to be in a hurry (even RTS with time-pausing induce a sense of a hurry and prevent slow perfectionist play-style). The rest of my view-point is that turn-based can be seen as realistic, with certain, more or less rigid, assumptions about squad tactics and combat psychology. Perhaps in some combat scenarios such assumptions are realistic themselves, perhaps not...

Good luck with your next exam! :)

Anton:
Been a long time gone, and now my proposal seems partially implemented, is it not?

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