Nomads of the Fallen Star: Combat Mechanics

Turn-based RPGs are one of my favorite game genres. I grew up with lots of hours spent playing classics such as Tactics Ogre, Fire Emblem, Final Fantasy Tactics and cRPGs such as Fallout 1 and 2.

However, one of the annoying aspect of turn-based RPGs are the time it takes to fight a battle, particularly as the size of battles grow towards the late-game. When lots of units take their turns, even simple animations or actions shift the time spent waiting versus playing ratio towards the “this is dragging on forever” zone.

As such, I wanted to make a turn-based RPG where the player is given all the time to decide, but actions resolve quickly for both player and NPC units.

Another factor is the map size, while it is easy to fall into the trap of making the playable combat area huge, I decided to keep the grid small to make combat happen quickly as both sides enter the fray within the first turn. This is especially useful for smaller scale battles, where players can quickly finish the combat and move on instead of wasting time crossing a large map to get into combat.

After a period of indecision, I decided to go with a chess-like grid combat system. However, instead of 8 x 8, it had to be longer to accommodate different range weapons that the units can wield. So I extended the board a little, and finally combat takes place on a 8 x 10 chess board.

Because of the chess-grid, the logical step was to represent Characters as chess pieces. I thought about the entire character, however, their faces became too tiny to appreciate, so I went with just their upper torso and and focus on the head.

Below, I’ll cover some mechanics, weapon design and armor system while showing a sequence of screenshots of a battle our rookie squad has gotten themselves into.

 

RPG elements: Character Stats and Skills

Each character have four main attributes, Strength, Agility, Vitality and Intelligence. These are immutable, and define the character’s potential.

Strength contributes primarily to melee damage and melee penetration, it partially affects blocking with shields and melee accuracy. It also determines what armor and weapon the character can wield.

Agility contributes to dodge, parry and block and weapon (melee & range) accuracy.

Vitality primarily determines Hitpoints, but it also reduces the duration of negative status effects.

Intelligence determines the rate of skill gains when characters level up. In combat, it affects accuracy and critical hit chance.

For the character skills, I decided to not include a plethora of skills, and focus on the combat related skills only. The non-combat skills that other RPGs tend to have (ie. social & flavor), I have separated them out as Perks that each character can obtain instead.

The combat skills are: Melee, Defense, Dodge, Firearm, Sniping and First Aid. The skill-based system is antagonistic, for example, Melee & Firearms skill contributes to accuracy, however, when a target is selected, the target’s Dodge skill will directly counter and lower the accuracy chance.

This gives the option of players or NPCs to specialize in agile, lightly armored and highly evasive units that are effective early all the way to late-game. However, skill-points are finite and most characters will not receive many each level, and so specialization is critical.

Characters that specialize in long range combat, ie. sniping, will need both Firearm skill for accuracy of rifles and Sniping to reduce the accuracy drop-off at long range. Meanwhile, characters that specialize in short range combat can instead take Dodge or Defense to boost their durability.

 

Movement & Initiative

The order that units act (initiative) is determined by their speed. Speed is affected by the unit’s Agility, Strength and the type of equipped armor. Lightly armored units will usually act first.

The combat is Action Points based, where each unit has a certain amount of AP each turn to move, attack, use items or abilities. The amount of AP a unit has is only determined by the type of equipped armor. Heavier armor will reduce available AP, and so a bulky character while heavily protected, will move and fight in a restricted manner compared to those who are lightly armored.

Humanoids without armor have a base AP of 9. Light Armor reduces it to 8, Medium Armor reduces it to 7 and Heavy Armor reduces it to 6.

Each grid movement costs 2 AP. It is important to note that units engaged in melee cannot move away, trying to do so will provoke an opportunity attack. As such, positioning of melee units are vital. There is no Perk or ability to bypass this rule.

Most weapon attacks cost 4 AP. Long Rifles cost 5 AP to fire.

Special weapon attacks tend to cost 1 extra AP above the base attack cost.

The only way to obtain extra AP is through Perks or Drugs (consumable items).

 

Weapon Types

In designing the weapons, I took care to not have any single weapon type much better that it overshadows all the other weapons. Each weapon type has to be meaningful and excel at a certain role in combat to justify their existence.

There are 8 weapon types that are commonly used by NPC humanoids and the player’s squad. For each, I will describe the role I intended for them.

 

 

Swords (1-Hand): A versatile melee weapon, with an innate bonus to Parry. It has low armor penetration, making it less useful against heavily armored targets.

Special attacks: Power Thrust and Twin-Slash.

Spear (1-Hand): A defensive melee weapon, the longer range grants the user a bonus to evasion against melee. It has good armor penetration, though lower damage potential.

Special attacks: Double Thrust and Impulse Drive.

Pickaxe (1-Hand): A good melee weapon for offense. It has good armor penetration and high damage potential. There are no defensive bonus, instead, it has a bonus to causing more damage to armor and shield durability.

Special attacks: Concussive Blow and Head Hack

Greataxe (2-Hand): A brute force melee weapon intended for pure offense and area damage. Forgoing a shield, a Greataxe wielder gains tremendous damage potential and a high damage bonus against armor and shields.

Special attacks: Leg Breaker and Wild Cleave (frontal AoE).

 

Handgun (1-Hand): A short range large caliber revolver pistol, intended for high damage potential against low armored targets. A good support range weapon that allows the unit to perform the role of a tank with a shield equipped. Can reach 3 grids, however, accuracy is only good to 2 grids.

Special attack: Head Shot (range weapons loose one special attack for reload).

Shotgun (2-Hand): A close range high damage but low penetration weapon. Devastating against lightly armored targets, while losing it’s effectiveness against strong armor. Can only reach 2 grids, though there is a high accuracy bonus for adjacent point-blank targets.

Special attack: Double Tap

Burst Rifle (2-Hand): A medium range rifle with an inaccurate burst fire option. Good armor penetration with moderate damage potential. Highly effective against targets that have low evasion.

Special attack: Burst Fire

Long Rifle (2-Hand): A high-powered but slow long range rifle. Strong single target damage, with high armor penetration. Inaccurate at close range.

Special attack: Head Shot

Firearms require munitions to fire and reload, with the rifle weapons using more expensive munitions.

All range weapons also have Line of Sight penalties. In trying to attack a target that has an allied unit in front and blocking the path of the projectile, a major accuracy penalty is applied. There is no penalty however, for shooting over your own units, so you can position range units behind melee to support.

 

Bomb Items:

Through crafting or sold at towns, there are several bomb types that can be equipped in the 2x Item slots that each character has.

Bombs are unique in that there is no throwing skill to use it. They can be thrown in a short range and affect all adjacent grid upon impact, ie. 9 grids in total, including the center.

Bomb blasts are also unavoidable. As such they are very powerful additions to your squad as well as something to be wary against from NPCs. Avoid clustering your units, NPCs are smart enough to decide where to throw for best AoE impact.

There are 2 damage focused bombs, Fire Bombs which sets the targets on fire, burning over time, and fragmentation Pipe Bombs that does high area damage but reduced by armor.

There are also “debuff” bombs. Daze Bombs which explodes with paralysis gas, reducing the AP of afflicted targets for several turns. Flash Bombs which explodes in a blinding light, causing temporary blindness to afflicted targets.

 

Support Items:

With only 2 Item slots per character, players have to pick wisely what to bring into combat. There are two main healing items, a low cost Salve Bandage with healing herbs that slowly heal over time, and an expensive high-tech Stim that heals wounds quickly over time. With poisonous Xenobeasts to contend with, having someone with an Antidote is also vital.

The final support consumable items are performance enhancing Drugs, which gives a user temporary bonuses in combat.

 

Armor Mechanic:

The guiding principle for me when it comes to designing the armor system is the job of Armor is to block the potential damage, or if not possible, then reduce it. Strong armor can completely nullify weak attacks.

I’ve always liked the armor system in Fallout 1 & 2, with a Damage Resistance (DR) and a separate Damage Threshold (DT) mechanic.

DR reduces incoming damage by a %, then DT will reduce it by a flat amount. Any damage left will impact the unit’s Hitpoints.

Under this scenario, an attack for 20 damage with 0% armor penetration against an armor with 30% DR and 5 DT will result in: (20 * 0.7) – 5 = 9 damage inflicted.

A multi-hit attack of 3x 8 damage against the same armor: (8 * 0.7) – 5 = 0 damage 3 times, because any decimal is rounded down.

In general, a strong single attack is more effective against resistant armor, while multiple weaker attack is more effective against lightly armored targets.

 

Combat AI:

The AI is designed to exploit your squad’s weakness and maximize their strength. Melee and range units will behave accordingly, snipers will maintain range, and move back if they must. Flanking units will try to avoid your melee tanks and go around them to reach more vulnerable targets.

The AI will use healing items, drugs and bombs if the opportunity present themselves.

Finally, there is no retreat once in combat. The player will be given opportunities to avoid combat on the world map, but choosing to partake in combat the option to retreat is nullified.

Instead, both player and NPC units that suffer morale loss will panic and their combat potential drops significantly.

In the wasteland, it’s a fight to the death, always.

 

Looting:

After a victory, your squad will scavenge the battlefield for goods and usable equipment. As such, anything the enemy have in their inventory can be available for looting, making combat potentially very lucrative.

For equipment, whatever armor or weapon that isn’t badly damaged during the fight enters the loot tables as possible loot. Likewise, unspent munitions are a precious find too.

 

---

 

Finally, I’ve also decided on the name of this game, Nomads of the Fallen Star.