Issue #1 – Combat Mechanics

Combat in SCTA works in phases. Each faction in the battlefield gets a phase, and the order of the phases depends on who initiated the combat. If the player initiates the combat (through dialog, ambush, etc), the player will always get the first phase.

Each tile is 4′ x 4′ in real world measurements.

Once the phase begins, the player can move any units on his side around the battlefield. Every step a unit takes triggers a Fieldcraft (self) vs Perception (others) challenge against enemy units within visual range or hearing range, with range as a modifier.

Before we go into the exact calculations for combat rolls, I’ll need to explain the concept of modifiers in Challenges.

Modifies in Challenges

Recalling the Magnum formula from the last update:

CL = Challenge Level
RL = Resistance Level
SP = Success Probability ( -109 to 144 )
NSP = Normalized Success Probability ( 13 to 266 )
SR = Success Rate ( 5 to 95 )

Calculating SP

SP = CL – RL

CL can either be:
CL = Skill or
CL = ( Attribute x 5 ) + Level

RL can either be:
RL = ( Attribute x 5 ) + Level or
RL = ( Resistance x 5 ) + Difficulty Level

Calculating SR

NSP = 144 + SP
SR = ( NSP + SP ) x 0.357

Modifiers are applied to the Success Rate (SR), where they modify the final results by x%. Modifiers can either be positive modifiers (bonuses) or negative modifiers (penalties).

For example:

A has 75 skill points in Sidearms
A is firing an SMG with a reflex sight, which gives a +10 modifier.
A is firing against an opponent 5 tiles away (SMG maximum range: 5, minimum range: 1, effective range: 2)
B has 4 agility and is level 15

The modifier for range would then be -30

[@][-45][0][0][-30][-60] (firing further than maximum range would incur a flat -90 mod)

Thus, when it is applied to the SR:

SR = ( ( 144 +( 75 – ( 5 x 4 + 15 ) ) ) x 0.357 ) x ( 100 – 30 + 10 ) / 100
SR = 53% (52.5504 rounded UP)

Without the reflex scope:

SR = ( ( 144 + ( 75 – ( 5 x 4 + 15 ) ) ) x 0.357 ) x ( 100 – 30 ) / 100
SR = 46% (45.9816 rounded UP)

Conclusion

Thus, the reflex scope’s +10 mod eventually adds up to a 7% increase in accuracy.

Another example pits a master rifleman against an average bandit:

A has 110 skill in Light Firearms
A is firing a sniper rifle ( 10 maximum range, 2 minimum range, 4 effective range ) with a tactical scope (+3 minimum range, +4 effective range, +4 maximum range, +30 mod within effective range)
A is firing at an opponent 12 tiles away
B has 4 agility and is level 15

Range modifier without scope = -90
Range modifier with scope = 0

Without scope:

[@][-60][-30][0][0][0][0][-18][-36][-54][-72]

SR = ( ( 144 + ( 110 – ( 5 x 4 + 15 ) ) ) x 0.357 ) x ( 100 – 90 ) / 100
SR =  8% (7.8183 rounded UP)

With scope:

[@][-75][-60][-45][-30][-15][0][0][0][0][0][0][0][0][-45]

SR = ( ( 144 + ( 110 – ( 5 x 4 + 15 ) ) ) x 0.357 ) x ( 100 + 30 ) / 100
SR = 95% (101.6379 capped at 95)

That’s a difference of 87% due to the range modifiers on the scope (+3 min range, +4 eff range, + 4 max range)!

Combat System

Having explained the modifiers and how it applies to challenges, it is time to explain how the combat system works.

There are two kinds of combat in the game: Ranged and Melee. Both operate on vastly different rulesets. I will explain the ranged combat mechanics today, and save the melee combat mechanics for some other day.

Ranged Combat Mechanics

Ranged combat commences when a unit fires at another unit. The following happens:

1. Challenger initiates a Weapon skill-to-Agility challenge for every bullet fired (in burst mode, apply the burst penalty on weapons). Range, concealment, cover and item mods are applied too.
2. Upon success, a penetration check (range from 1 to 12) is made against the armor’s damage threshold (range from 0 to 6).
3. Upon successful penetration, a damage check is made.
4. The resulting amount of damage is then applied to the enemy unit’s HP

Here are the juicy formulas:

Bullet Penetration Types:

• Pellet = 1D3 + Caliber
• Slug = 2D2 + Caliber
• Tungsten Slug = 2D3 + Caliber
• Jack Hollow Pocket = 1D3 + Caliber
• Full Metal Jacket = 2D2 + Caliber
• Armor Piercing = 3D3 + Caliber
• Micro Explosive = 2D3 + Caliber

Caliber Bonus:

• 10mm, .38, 12ga = 0
• .357, .45 = +1
• 5.56 Short, 7.62 Short, slug = +2
• 7.62 Long, .303 = +3
• .50 = +4

Armor Absorption Types:

• None = 0
• Fabric = 1
• Leather = 2
• Hardened Leather = 3
• Kevlar = 4
• Metal = 5
• Ceramic = 6

Penetration Level (PL) = Bullet Penetration Roll – Armor Absorption

Penetration Level Modifier to Damage:

• 0 or below = no penetration
• 1 = 100% damage – Armor Damage Reduction
• 2 = 120% damage – Armor Damage Reduction
• 3 = 140% damage – Armor Damage Reduction
• 4 = 160% damage – Armor Damage Reduction
• 5 = 180% damage – Armor Damage Reduction
• 6 = 200% damage – Armor Damage Reduction

At this point I think I need to differentiate between RPG mechanics and game mechanics. RPG mechanics concern the design of the RPG system, skill challenges and so forth – high-level stuff where you can easily replicate and prototype them on paper (with the help of a D100 generator). Game mechanics on the other hand, defines how the game engine works, and must be tested along with the development of the engine itself.

While the weekly updates have done a fine job in explaining the RPG mechanics of the game, the actual game mechanics are yet to be fleshed out. I hope this post would do a better job in explaining how the game actually works.

Visuals

For all 3 tactics game, as well as the RPG trilogy, we will be using a 2D isometric engine with art assets recycled from the previous games. In this sense, the tactics series are very important as they establish the art direction for the rest of the series.

The first tactics game will take the longest to release, as it needs to flesh out the game engine and the initial art assets. It is in this game that the common sprites like: merchants, villagers, townsfolk, raiders and slavers will be created, as well as most of the different units from the Awakened faction. Just a reminder about what SCTA 1 is about: it’s about the Awakened Order’s efforts in fighting off an increasingly organized bandit force in the Oasis to protect the merchants.

The second tactics game will reuse most assets from the first game, as the game happens in the same location (Oasis), but will add in extra unit assets from the Saberion faction. Also, it will add in interior art assets as well, to model the Saberions’ assaults on Awakened bunkers. SCTA 2′s story is about the Saberion’s incursion into the Oasis after being flushed out of the Gloomy Tunnels by the Combine, and the subsequent misunderstandings between both sides that lead to much bloodshed.

The final tactics game will reuse all the previous two games’ assets, but will add in ruined cities assets as well as unit assets from the Combine. Also, flakies and bahamura agents will be added in as well. SCTA 3′s story revolves around the Combine’s siege of Oasis to both wipe out the Saberions and to conquer its resources, as well as the Awakened Orders’ efforts to prepare for the eventual exodus from Oasis.

Destructible Environments

Environments in both SCTA series and the RPG trilogy are mostly destructible. Doors, locks, furniture and fences can be shot through or destroyed by small arms fire, unarmed strikes or melee weapons. Some walls too can be destroyed with explosives or demolition charges. In addition, fuel and gas tanks can also be destroyed with either tracer bullets or explosives, or a lucky shot with a rifle-caliber weapon or shotgun burst.

This is to create a battlefield with a heightened sense of realism where there are endless approaches to the same problem if one has the right tools and knowledge.

to be continued…

Issue #1 – Wounds and Bleeding

Hit Points or Health Points in RPGs have always bothered me. In a way, they are poor abstractions of a person’s physical capacity in battle. In real life, one hit to the right spot is usually more than enough to incapacitate a person, and even after surviving such a wound, one wouldn’t be able to perform at full capacity at all.

In fact, in the real world, the moment you receive a serious wound, you’re disadvantaged. However, in RPGs, even when your 200 HP character is reduced to 2 HP, he can still fight, and even win a battle.

There are ways to justify such a system. However, regardless of what reasons, I still don’t think a person with 2 HP should function similarly to a person with 200 HP.

Therefore, I’ve added the element of wounding and tie it into morale.

Firstly, the amount of HP that a person has refers to his ability to absorb and endure injury. This can either be explained through adrenaline or sheer willpower. There are countless cases where a person keeps fighting even after sustaining supposedly incapacitating wounds, and most of these cases can be attributed to a combination of an iron will and adrenaline rush.

Experience levels also contribute to the total HP of a character. The reasoning is simple – the more experienced a person is, the more injuries the person would have sustained (and healed from), which reduces the psychological impact of the injuries in the first place. Note that having HP down to zero does NOT mean a character is dead. It merely means a character is incapacitated, which depending on the nature of the wounds may or may not also mean that the character is dying or dead.

Here’s how it works:

• 100% HP = 100% capacity
• 50% HP = 50 + (Level / 2 )% capacity
• 25% HP = 25 + (Level / 3)% capacity
• 10% HP = 10 + (Level / 3)% capacity
• 0% HP = incapacitated

Let’s test this with a “n00b” level 1 character with 1 Constitution and 1 Willpower:

HP = 30 + (CON x 2) + (WIL x 2) + (Level / 2)

HP = 30 + 2 + 2 + 1 = 35

• 35 HP (100%) = 100% capacity
• 17 HP (50%) = 51% capacity
• 8 HP (25%) = 26% capacity
• 3 HP (10%) = 11% capacity
• 0 HP = incapacitated

For a “normal” level 1 character with 5 Constitution and 5 Willpower:

HP = 30 + (CON x 2) + (WIL x 2) + (Level / 2)

HP = 30 + 10 + 10 + 1 = 51

• 51 HP (100%) = 100% capacity
• 25 HP (50%) = 51% capacity
• 12 HP (25%) = 26% capacity
• 5 HP (10%) = 11% capacity
• 0 HP = incapacitated

Let’s test the values again, this time assuming that both characters have gotten to level 30:

Character A (“noob”):

HP = 30 + (CON x 2) + (WIL x 2) + (Level / 2) = 30 + 2 + 2 + 15 = 49

• 49 HP (100%) = 100%
• 24 HP (50%) = 65%
• 12 HP (25%) = 30%
• 4 HP (10%) = 15%

Character B (“normal”):

HP = 30 + (CON x 2) + (WIL x 2) + (Level / 2) = 30 + 10 + 10 + 15 = 65

• 65 HP (100%) = 100%
• 32 HP (50%) = 65%
• 16 HP (25%) = 30%
• 6 HP (10%) = 15%

So as you can see here, an increase in experience levels mean a character will suffer less penalties when fighting wounded.

Of course, this is just the BASE efficiency. Morale needs to come into play here.

Morale is pretty basic. A character starts off at 100% morale, and depending on his actions he will either gain or lose morale. For example, if a character is wounded in combat, he loses morale. If a character scores a direct and verifiable hit on the enemy, he gains morale.

Here’s a table of what happens when a character’s MP is modified in combat:

• 101 – 200% – +1% efficiency per 2% morale gained
• 100% – no bonuses, no penalties
• 0 – 99% – -1% efficiency per 2% morale gained
• below 0 – willpower check every round. Panics if check fails

The efficiency is added to the base efficiency determined by the character’s current HP level. So, for example, the level 15 “normal” character is currently at 30HP, which gives him a base efficiency level of 65%. If the character’s current morale level is 120%, this gives an extra 10% to his efficiency level.

Note that efficiency has a range from 5 to 100. Anything below 5 will be capped at 5.

Issue #2 – Skill Challenges

How does the game handle skill challenges?

Challenges pit a skill/attribute against an attribute/resistance level. There is no such thing as a skill-to-skill challenge in the game mechanics.

Challenges are made when the player’s skill is required to overcome a difficulty that has the ability to resist the player’s attempt.

1. Trying to pry open a lock with a crowbar pits the player’s strength attribute against the lock’s resistance level ( Strength vs Resistance )
2. Trying to hit another character with a crowbar pits the player’s melee combat skill against the target’s agility ( Melee Combat vs Agility )
3. Trying to hack into a computer is a skill challenge that pits the player’s thievery skill against the computer’s resistance level ( Thievery vs Resistance )

To perform a challenge, the following formulas are used:

Skill Challenge Success Probability = Skill – ( Attribute x 5 + Level )
Attribute Challenge Success Probability = ( Attribute  * 5 + Level ) – ( Attribute x 5 + Level )

Normalized SP = 122 + SP

Success Rate = Normalized SP * 0.357

A note on resistance level though. Every item that offers a resistance level has two stats: resistance and level. Resistance refers to the TYPE of challenge in performing that task, while level refers to the actual difficulty of performing it.

Determining Resistance Levels

To determine how to assign resistance and levels, use this rule of thumb:

Resistance = Adjective (Range from 1-10)
Level = Object Type (Range from 1-60)

For example, a normal padlock would have a level of 1 (applies to all padlocks) and a resistance of 1 (“normal” padlock). A master-forged padlock would have a resistance of 2 (since it’s a well made padlock) and a level of 50 (“strong” master-forged padlock). Or, if the master-forged padlock had been left in the cellar for decades and have subsequently rusted internals (which makes it even harder to lockpick), it’ll instead of a resistance of 2 (it’s a master padlock all the same. The internals don’t change) and a level of 60 (since it takes more effort to pick the lock).

Here’s a handy example list:

• Comic Book – R1L1
• Frank Miller Comic – R1L20
• Comic Book with hidden messages – R1L60
• Chemistry for Dummis – R5L10
• Advanced Chemistry – R5L40
• Pre-Exodus Chemistry Secrets – R5L60

In short, resistance refer to how easy it is to perform the task, while level refers to the complexity of the task itself. Objects that have a high resistance but low level would be objects that are hard to understand but simple in nature (car engines, books, etc) while objects that have a low resistance but high level would be objects that are easy to understand but hard to manipulate (complex locks, disarming bombs, etc).

Personally, we can always change the resistance level to just range from 1-110, or even use a 10 + 1 point system to simplify matters. This would dramatically reduce the range of probabilities though, and make skill increments less meaningful too, so it’s a dangerous balance here.

I’ll change it in the future if this proves too much for game designers to implement in their world designs.

Analysis

As with all formulas, we need to test it. First we find out the min, avg and max scenarios to get a feel of whether the formula is working the way we envision it to or not.

For example, a player fires a shot with his 9mm pistol against an enemy. Let’s calculate the min, avg and max SP possible in this scenario:

Minimum Scenario:

- Player has 1 point in sidearms
- Enemy has 10 agility and is level 60

Min SP = 1 – ( 50 + 60 ) = -109

Average Scenario:

- Player has 75 points in sidearms
- Enemy has 5 agility and is level 30

Avg SP = 75 – ( 25 + 30 ) = 15

Maximum Scenario:

- Player has 150 points in sidearms
- Enemy has 1 agility and is level 1

Max SP = 150 – ( 5 + 1 ) = 144

Therefore, using the above calculations as a base, we can conclude that SP always lie between -109 and 144. We normalize this by adding 122 to SP, giving it a new range of 13 to 266.

We then further normalize this to 1-100 by multiplying it by 0.357 and then round UP the result, giving it a range of 5-95.

If the SP is 15, the success rate would be:

Success Rate = ( 15 + 122 ) * 0.357 = 49 (rounded up)

Similarly, if the SP is -109, the success rate would be:

Success Rate = ( -109 + 122 ) * 0.357 = 5 (rounded up)

And finally, if the SP is 144: 122

Success Rate = ( 144 + 122 ) * 0.357 = 95 (rounded up)

Using the lock picking example from above, it should be noted that for the same object, many different kind of challenges can be made with different levels of resistance level. There are a few actions that can be applied to a lock:

1. Lock pick = Thievery Challenge with R1L30 ( D35 )
2. Lock pick with Toolset = Thievery Challenge with R1L15 ( D20 )
3. Shoot/Attack the lock = Weapon Skill Challenge with R1L1 ( D6 ), damages lock HP

However, when dealing with an electronic lock:

1. Lock pick = Thievery Challenge with R1L60 ( D65 )
2. Lock pick with Hack Tool = Thievery Challenge with R1L30 ( D35 )
3. Shoot/Attack the lock = Automatic Failure

The Actual Roll

Now we’ve determined the Success Rate (SR) of the task intended. What do we do? Simple. We roll a D100 die, which gives us a result ranging from 1 to 100. Now, the Success Rate is called a success rate because it shows the probability of your character succeeding in the task. Therefore:

If the result is LESSER than the SR ( Roll <= SR ), the task is successful.

If the result is MORE than the SR ( Roll > SR ), the task is unsuccessful.

Simple eh?

Issue #3 – Effects of Efficiency on Skill Challenges

As mentioned in Issue #1, in combat a character’s efficiency drops when he takes either morale or HP damage. So how does this efficiency issue come into play in skill challenges?

The answer is surprisingly simple.

The skill challenge can be split into 3 steps:

1. Calculate Base Success Probability ( BSP: -109 to 144 )
2. Add 122 to the BSP to get the Normalized Success Probability ( NSP: 13 to 266 )
3. Multiply it by 0.357 to get the Success Rate (SR: 5 to 95 )

To calculate the efficiency into the formula, simply take the SR and multiply it to the efficiency percentage. Remember to round UP the results.

For example:

SR = 65
EF = 100%
FSR = ( 65 x 100 / 100 ) = 65%

SR = 15
EF = 90%
FSR =  ( 15 x 90 / 100 ) = 14%

SR = 95
EF = 5%
FSR = ( 95 x 5 / 100 ) = 5%

Therefore, efficiency is extremely important in a fight, which amplifies the impact of wounds and morale of a character.

Issue #4 – Name for Character System

This isn’t a big issue, but having a name for the mechanics is always good for branding (think Fallout’s SPECIAL system). I’ve decided to call this system the…

The Magnum System!

The name comes from the normalizer used in the challenge system: 0.357. For non-gun buffs, the 0.357 Magnum revolver caliber happens to be the one chambered for the Colt Python, which is one of my all-time favorite guns. A coincidence too, that the other normalizer, 122, coincides with Remington’s (one of my favorite shotgun maker) Golden Saber JHP 0.357 round, that boasts a muzzle velocity of 1220 feet per second with a One-Stop Shot rating of 81.7%.

Now that’s one hell of a magnum round that I won’t want to mess with!

Issue #1 – Attributes

Attributes determines the physical condition of a character. Unlike other RPG systems, attributes in this system is counted in levels, not points. Each attribute has 10 levels, and the player starts at level 5 (average). Depending on the list of traits chosen by the player during character creation, the attributes will be modified accordingly, which reflects in the skill point distribution.

Attribute levels do not increase or decrease with experience level. They stay consistent for the entire trilogy. They play a very important role in the game mechanics in defining a character, especially when it comes to skill challenges. A stupid person is still a stupid person even when said person had read all the books in the library. The only difference between a well educated stupid person and an uneducated fool is that the well educated person has a better chance of debating on a topic due to his extensive knowledge (Skill Challenge on Skill). He’ll face the same problem with the uneducated fool though when it comes to learning a new skill from a book (Skill Challenge on Attribute).

During character creation, the player is given 5 extra attribute points to spend.

• Strength – Intimidation, Crafting, Unarmed Combat
• Constitution – Heavy Firearms, Medicine, Engineering
• Willpower – Persuasion, Deception, Leadership
• Agility – Explosives, Sidearms, Melee Weapons
• Intelligence – Security, Memory, Science
• Perception – Awareness, Light Firearms, Fieldcraft

Issue #2 – Derived Attributes

Derived attributes have a direct impact in the game, where three of the four (except carry weight) are tracked constantly by the player to ensure that his character is performing at peak efficiency.

• Hit Points ( 30 + Constitution x 2 + Willpower x 2 + Level / 2 )
  Hit Points, or HP, describes the number of “hits” or the amount of physical damage a character can take before being incapacitated. When a character’s HP reaches below 20% of his base HP, a character becomes incapacitated (e.g. unconscious) and will need somebody to “stabilize” him using a medpack or similar item. Otherwise, the character will die after 5 rounds. Also, whenever a character is hit with a projectile or a bladed or pointed weapon, the character will receive a bleeding status which causes the character to lose HP every round. I will extend on this more in my wounds and medicine section.
  - Min: 38
  - Avg: 51
  - Max: 100
• Action Points ( 5 + Agility x 2 + Level / 5 )
  Action Points, or AP, denotes the number of actions one can do in one round. The faster a person is, the more actions one can perform per round (which is approximately 10 seconds per round). Unused AP when the character ends a round can be used if the character successfully rolls an intercept, and if no AP is used in the intercept (or if the player fails the intercept) it will be carried forward to the next round. A character can accumulate a maximum of 45 AP.
  - Min: 11
  - Avg: 21
  - Max: 37
• Morale Points ( 20 + Willpower x 3 + Intelligence + Level )
  Morale Points, or MP, denotes the psychological status of a character in combat. I have yet to work out the exact mechanics of this though.
  - Min: 25
  - Avg: 70
  - Max: 120
• Carry Weight ( 10 + Strength x 4 KG )
  Carry Weight denotes the amount of stuff one can carry. Note that this is not the EXACT tonnage of a person’s carry capacity, but perceived weight. For example, if a character attaches a sling to a 5kg rifle, it will reduce the rifle’s perceived weight by 1kg even though in reality this only adds to the nett weight of the rifle.
  - Min: 14 KG
  - Avg: 30 KG
  - Max: 50 KG

Issue #3 – How skills tie to attributes

The character starts with 25 points in each skill. Upon creation, every increment in a particular attribute will result in a +5 to all related skills; on the other hand, every decrement in an attribute will result in a -5 decrease to all related skills too.

For example, if the player reduces Strength by 1, Melee Combat, Heavy Weapons and Small Arms will get a -5 to its base 25 points, ending up being only 20 points.

This is just the basics of how skill ties to attributes.

On the next update I’ll talk about skill checks, attribute failsafe checks and skill challenges.

There are 2 more weekly updates posted in the team forums, but I chose not to post them because I’m lazy I think they are not interesting enough. Just a couple of screenshots and stuff.

Issue #1 – Revamped Skill System

When I was writing the previous character stat system, I started to wonder – can this fit into our universe? Ideally, I’d like to use the exact same mechanics for all the tactics game as well as for the RPG trilogy which is the eventual goal of the Splintered Core universe.

No, the current one would not do. Instead, I started out by defining the mechanics of the RPG instead, which is much more complex than the one used in the tactics game. I figured that by doing so I’d be able to retardize simplify the mechanics once I’m done with it to fit into the tactics game.

The mechanics for the RPG is a heavily skill-based system, where most of the character’s action in the wildlands are affected by the level of proficiency he has on various skills.

I am a person who likes neat and tidy things, and thus I created a 18 skill system that is tied to 6 attributes.

Here’s how it works:

Combat Skills

• Sidearms – usage of pistols, revolvers and submachine guns
• Light Firearms – usage of shotguns, carbines and rifles
• Heavy Weapons – usage of machine guns, flame throwers and mortars
• Explosives – usage of grenades, dynamites and shaped charges
• Unarmed Combat – hand-to-hand combat
• Melee Weapons – usage of melee weapons

Social Skills

• Intimidation – capability of imposing fear onto others
• Deception – capability of deceiving others
• Persuasion – capability of convincing others and debating issues
• Leadership – capability to rally and inspire crowds
• Awareness – speed in collecting and processing sensory data
• Memory – capability in storing and retrieving data mentally

Utility Skills

• Fieldcraft – ability to utilize terrain for cover and stealth
• Engineering – knowledge in maintaining and repairing mechanical objects
• Medicine – knowledge in healing and dealing with wounds and diseases
• Security – ability in picking locks and pick pocketing
• Science – operating terminals, computers and gadgets
• Crafting – ability to craft and repair items

Each skill ranges from 1 to 150.

In the next update I’ll write about how skills tie to attributes.