Turn-Based Tactics: a Battle System

Published on 30th July 2009 by Colm | Post a comment

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We're building a fairly simple game featuring turn-based battles with fantasy units. This is the skeleton of the battle system I've devised – I'd love any feedback or comments anyone has to help me improve it.

Overview

The game is a turn-based tactics game where you start with a small warband of rookie units, then fight battles with them. Doing well in battles can improve your units, and give you money to expand your warband or improve the equipment of your existing units. It will be a single player game.

Battles

Battles take place on fairly small square-based maps (top-down), probably under 20×20 tiles. Your warband will start with about 3-5 members and probably max out around 10, so battles shouldn't be massively long affairs. You win by eliminating the enemy.

Battle System Goals

  1. Be simple & easy to understand at first
  2. But have emergent complexity
  3. Have an element of chance, but not be ruled by it
  4. Be fun to play through each battle (tactical choices + challenge)
  5. Be rewarding to build up your warband over time (strategic choices)

Units

Each unit is a fantasy-themed warrior with the following stats:

  • Speed: squares moved per turn (avg 5)
  • Health: Damage taken before being removed from battle (avg 20)
  • Strength: Ability with melee weapons (avg 5)
  • Agility: Ability with ranged weapons (avg 5)
  • Armor: Depends on equipment

Units can also have skills though most will start as rookies with no skills. Skills will give new abilities and are the main vehicle for 'emergent complexity' where combinations of skills will yield new & interesting tactics.

Units' battle power will largely depend on their equipment, particularly as rookies. This can be upgraded between battles. Units will be of a certain type/class that will dictate their skill choices (eg infantry / archer / scout / cavalry).

Attacks

Each turn a unit can move and then attack. Range of melee weapons is adjacent; for ranged weapons it is adjacent + diagonally. When you move into a square next to an enemy (their 'zone of control') your move ends (though you can still attack them), meaning you can't run through to target the weaker/wounded enemy at the back.

When you make a melee attack you add your strength to the strength of your weapon and roll a 1d10:
1-2: miss
3-9: hit
10: critical hit

If you hit you add the roll value (3-10) to your attack strength to get a damage total. The target's armour value is then subtracted from this to get the actual damage sustained. A critical hit means the target's armour value is halved for this attack. Also some weapon types have some special rules, explained below.

Ranged weapons work the same way except you add your agility to the weapon strength, and the enemy can only counter-attack if they are also using a ranged weapon.

Counter-Attacks

If a unit survives an attack they immediately attack the unit that attacked them, using all the normal attack rules. Each unit can only make one counter attack per turn, no matter how many times they are attacked that turn. A unit with only a melee weapon cannot counterattack when attacked by a ranged weapon. A unit with a ranged weapon attacked by a melee unit counterattacks with their knife rather than their ranged weapon.

Equipment

All equipment is of a certain type with basic rules governing it; within each type there are actual items of varying cost & power (eg of type sword: short sword, long sword, fine broadsword, etc)

Armour Types:

  1. None: +0 to armour; no penalties.
  2. Leather: +1-3 armour; no penalties.
  3. Chain: +4-6 armour; slight penalty to speed and medium penalty to agility
  4. Plate: +7-10 armour; medium penalty to speed and high penalty to agility
  5. Shield: +1-4 bonus to armour; bonus doubled vs 1st attack sustained each turn (shield block)

Weapon Types:

  1. Knife: free for all units (eg ranged units), allows basic melee attack with +0 strength
  2. Sword: versatile melee weapon; +strength based on quality of sword (eg short sword: +1, long sword: +2, etc); allows 'parry' which adds strength to armour vs 1st attack sustained each turn (vs melee only)
  3. Axe: offensive melee weapon; +strength based on quality but higher than comparable swords (double?); bonus vs shields (bonus halved?)
  4. Spear: defensive melee weapon; +strength based on quality, similar power as comparable swords; bonus to +strength when counter-attacking; allows 'first-strike' when attacked which lets you deliver your counter-attack before the enemy makes their attack
  5. 2-handed sword/axe: same special rule as 1-handed version but higher strength (eg +4); can't use shield
  6. Bow: Ranged attack (uses agility; can attack diagonally; melee units can't counterattack); can't use shield

Thoughts

The main goal here is allowing a fairly complex 'emergent' set of tactics from a simple enough system. Things that allow this are the choices of weapon types vs different targets; positioning during battles being important (ganging up is best, but difficult due to zones of control). Your first battle would feature pretty much all of the above.

Later you would add some more complexity with the 'skills' units gain as they level up. For example a scout type of unit could choose 'Evade' which lets them ignore the first zone of control they walk into each turn, and so on.

We're currently putting all this into our game prototype to play around with it; we'll feed back on what we think works in the future. Oh and if you've gotten this far, you must be some sort of hardcore turn-based strategy / RPG nerd, so give us some suggestions we could use to make the battle system better!

Posted in: Game Development |

Thanks for reading! Now check out Guild of Dungeoneering, a game I'm making where you build the dungeon instead of controlling the hero! \o/
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12 Comments

  1. The system looks to be well thought out. Off the top of my head, I would throw a little randomness into the ability to perform a counter-attack based on agility and speed. As is, a counter attack will almost always be made and that will effectively hamper any need for unit placement strategy, as it will give way to the idea, "My strongest character will just intercept any enemies and counter-attack them to death." Perhaps I am missing something, but that is the thing that immediately stood out to me. Best of luck – I look forward to playing.

    Posted by Jacob on July 30th, 2009 at 2:25 am
  2. Agreed on the comment by Jacob re: speed and agility being factored into counterattack "randomness".

    I think it might also make a bit of sense to put a negative modifier on the damage delt during a counterattack. Even if you're wearing plate, being hit by a 2handed sword at full speed can throw you off a bit. :)

    Posted by wazoo on July 30th, 2009 at 8:00 am
  3. Thanks for the feedback. That's not a bad idea about counter-attacks; at the moment you can't just put a super-strong character standing out front intercepting everyone because they will only get to counterattack once per turn. Adding a little randomness to that fact could work very well though!

    Posted by Colm on July 30th, 2009 at 9:28 am
  4. Nice work. The only things I would change would be the attacks.

    Ranged units don't seem to have the advantage of range. Perhaps allow them to shoot over 2 or three blocks, rather than just one. This gives archers the advantage that they were originally created for – pelt the enemy before they get close enough to do damage. Also, you could then limit the armor they could wear, as you can't really shoot a bow or reload a crossbow in plate. Alternatively, you could make ranged units use their agility to hit rather than strength which means that their armour would affect their accuracy, but this means you'd need to factor penalties into the attack before determining hit/miss.

    Weapons like the spear were designed to allow for reach – an enemy cant reach you with his sword if he's dangling on the end of your spear. Perhaps keep the 'adjacent' rule, but allow spearmen two blocks of reach.

    With the shield, to eliminate the initial complexity, why not make Shield Block an ability that units can learn.

    @Jacob – I disagree with you. The fact that units may only make one counter-attack per turn means that you could easily overcome the 'strongest character' with numbers rather than force.

    Posted by Matt on July 30th, 2009 at 9:45 am
  5. Thanks for the suggestions (and RT) Matt.
    I'm not totally sold on what I've come up with for ranged attacks (just being diagonal rather than a few squares like you say), so it's definitely one of the aspects to be scrutinised and tweaked in playtesting.
    Ranged units already use agility instead of strength – not exactly in a roll 'to hit', but in the exact same way strength is applied to melee attacks; and the heavier armours will give big agility penalties, making ranged weapons + heavy armour a bad idea.
    I've also not been able to think of a nice elegant way of differentiating bows (faster) vs crossbows (slower, armour piercing) in the current system. If ranged weapons could attack at say 3-4 squares range then it would be doable to make crossbows more powerful / piercing but only allow you to move OR shoot with them.
    Finally, thanks for the shield/spear suggestions. Spears in particular don't feel quite 'right' and will hopefully make more sense when we get to try them out.

    Posted by Colm on July 30th, 2009 at 10:57 am
  6. I can't help but think of Dragon Warrior 1 with the weapons and armor you have, good stuff. As far as the system itself goes, sounds pretty quality. I like the idea of focuses more on tactics and keeping the stats out of it as much as possible, while still keeping it an RPG of course. I've been wanting to do something like this for a very long time. I think I'll hop on it once I have enough money to afford some time to play around.

    Posted by Porter on August 29th, 2009 at 3:32 am
  7. That's interesting about Dragon Warrior; having read up about it (never had a NES!) I'd agree its weapon/armour system is also pleasantly simple. I've got most of the battle system into a working prototype, giving me a chance to actually play it a bit. I'm now looking at making unit stats even more simple (combining STR and AGI into 'attack power' for example), but am finding differentiating weapons & units into interestingness a little tougher. More on this in the future :D

    Posted by Colm on August 31st, 2009 at 4:45 pm
  8. I haven't really read everything in detail, but the bottom line is that you have your system sorted out preety good. All of those are classic elements, tested and working :) Keeping the system simple should make battle strategy preety important.

    For some time now I've been playing the Battle for Wesnoth which is very similar to your ideea. I find their battle system to be very effective and strategy is a key to victory :) No, archers don't shoot from a distance of more than one tile, but they can't be counter-attacked by melee units.

    Have you considered enviroment's role in the battle system?

    Good luck!
    Claudiu

    Posted by Claudiu on October 13th, 2009 at 9:34 am
  9. [...] 2009 sees a lot of vital improvements after spending some time designing our basic battle system. Zones of control are in (once you move next to an enemy you can't move further), and units now [...]

    Posted by Screenshots From The Past Year | Gambrinous Blog on February 1st, 2010 at 1:53 am
  10. Aahh what do I see… there is no wizard, mage, cleric and similar units. You're not winning the players in love with that type of unit (even if it only uses fireballs or lightnings). Good luck anyway

    Posted by Stef on March 23rd, 2011 at 9:00 am
  11. I forgot: For wizards etc, you could see what I mean by trying Spectromancer: http://www.archipelago-of-strategy-games.com/games/Spectromancer-League-of-Heroes_fantasy_game.html
    It's pretty addicting and very original

    Warlords 2 has also more unit types than you do. It's easier to get the player interested in this type of universe.
    http://www.archipelago-of-strategy-games.com/games/Warlords-2-Rise-Of-Demons.html

    My two cents…

    Posted by Stef on March 23rd, 2011 at 9:03 am
  12. Sounds good so far. The only thing that i am thinking of is maybe taking into account the atmospheric conditions for the ranged attacks.
    maybe later there will be a weapon degrading and repair system? just a thought.
    overall keep it up looks good

    Posted by roguelikemonkey on June 3rd, 2011 at 4:53 am