Sunday, March 8, 2009

Combat Mechanics for Modified GURPS

Continuing from yesterday-- a summary of Combat Mechanics. Gene has me looking at BESM 3e, so I have to go through that as well. Basically I'm trying to work through how thinly I can slice the rules and still have it taste good. This is another game mechanics post, so if that's not your bag, feel free to skip.

COMBAT
Combat will be a simplified version of the Gurps combat system. We're leaving off a lot of the most crunchy bit and focusing on play and strategic choices.

ACTIONS
On your turn you get a MOVE action plus another action. Your MOVE is equal is the number of yards you can cross in an action. Armor and Equipment may slow you down. Your second action may be one of the following:

ATTACK
FEINT
ALL-OUT ATTACK
AIM
FULL DEFEND
MOVE
CASTING/PREP
CONCENTRATION
COMPLEX ACTION
LONG ACTION


Additionally, it is assumed you can do small actions freely on your turn: looking around, drawing a weapon, shouting orders and so on. The GM may allow players to forgo their MOVE in order to do something a little more complex and still take their normal action-- this might include doing a full survey of the battle to assess things, kicking an obstacle into place, finding something specific in your bag and so on.

Attack
To make an attack you have to be in range. To make an attack with a ready weapon, you roll 2d10 and try to roll equal to or under your skill with that weapon. Circumstances and situation may modify your attack roll. If you roll under the modified number, you hit the target.

If a target is aware of the attack, they may try to defend. On each round a character may make one Parry, one Block (if they have a shield) and unlimited Dodges. A character's Parry is equal to (one-half their weapon skill) +5. Ranged attacks may not be parried without a special talent. Light weapons trying to parry enormous weapons get a penalty. A bare-handed character may only parry bare-handed attacks unless they have a special talent. Block is equal to (one-half their melee skill) +5. Some shields give bonuses. Dodges are equal to (Basic Speed) +5. Some area effect attacks give a penalty to dodges.

You can only make one defense roll against any attack. You usually only get one Parry and one Block per round.

If you hit and the target does not defend, you roll damage (see later).

Feint
To make a Feint you make a contested roll of your Weapon Skill versus the opponent's weapon skill. If your Bluff is higher, you may use that for performing a Feint. If a person's Sense Motive is higher than their weapon skill, they may use that for resisting a Feint.

If you win the contest, the margin of victory is subtracted from the target's active defense rolls against you until after your next action. You may declare your Feint as affecting another person also engaged in combat with the target-- handing the defense penalty to that person's attacks against the target.

All-Out Attack
If you choose to make an All-Out attack, you lose your active defense until your next action. You may make a Defense roll against attacks you are aware of, but you have to roll a 5 or less. This number is not modified by any other abilities (with some exceptions). You may only make an All-Out attack with a melee/HTH attack.

An All-Out Attack maneuver allows you to:
*Make two attacks against the same target or one attack each against two targets within reach.
*Make one attack at +5 to hit.
*Make one attack at +3 damage
*Make a Feint immediately followed by an Attack
*Move twice and then attack.

Aim
If you are using a ranged weapon, you may Aim to give yourself a +5 to hit on the following attack.

Full-Defend
If you take a Full-Defense you may either:
*Add +3 to your Defense roll of one type (Parry, Dodge, Block) until your next action.
*Roll two different Defense rolls against attacks until your next action. Remember, you usually only get one Parry and one Block per round.

Move
Move a number of yards/spaces equal to your Move value. Move is usually based on your Basic Speed, modified for armor and encumbrance. Standing up after being knocked down is a move action, unless you make an Acrobatics check.

Casting/Prep
Non-ritual spells require one action to Prepare and one action to Cast. If a caster has applied the Fast modifier to their spell, Prep and Casting can be done in a single action.

Concentration
Where a caster is controlling something at a distance or something of the sort, the GM may require them to spend their action Concentrating. If they are struck while Concentrating, the GM may require them to make a WILL check to remain focused.

Complex Action
This is essentially any non-attack action which might require a skill test to perform.

Long Action
Anything that requires multiple rounds to pull off-- like reading a book or rebuilding a broken device.

DAMAGE
Characters have a base damage they deal based on their Strength (ST) stat. This base damage comes in two forms-- Thrust (TH) and Swing (SW). Weapons do damage in various types, usually with a bonus listed to the character's base damage. None of this is actually complicated in play, since you'll record your damage on your character sheet.

As an example of damage, Scott has an ST of 13-- that means his base damage is 1d6 for TH and 2d6-1 for SW. He's using a Thrusting Broadsword-- it does TH+2 Impaling damage or SW+1 Cutting damage. So he'd roll 1d6+2 for a thrust attack or 2d6 for a cutting attack. Keep in mind with damage, when you get to +3 in bonuses, you jump up to the next die -1.

Basically, there's three kinds of damage-- measured by how much extra damage it does after Armor. A Crushing attack does straight damage, a Cutting attack does +50% damage, and an Impaling attack does double damage. Again, this is relatively easy to calculate on the fly. Armor has Damage Resistance (DR) which is directly subtracted from the damage.

As an example, let's say Scott's hitting a guy with Heavy Leather armor, DR 3. If he does a thrust attack, he rolls 1d6+2...let's say he rolls a 3 for a total of 5. That means two points gets through, which is then doubled so the target takes four points. If Scott had been Swinging he would have rolled 2d6...let's say he rolled 7-- less the 3 DR means 4 gets through, which becomes 6 after we add the +50%. Again, the GM's used to these calculations and can do them very quickly.

Damage is subtracted from your HP. On the round after you've been hit, you have a penalty equal to the damage you took. This applies to Attacks, Casting and Concentration but not Defense rolls. If you take more than half your HP in a hit, you have to make a Health (HT) check to avoid being Stunned. When you hit 0 HP you have to make a HT check to stay up-- when you reach below 0 HP you have to make HT tests each round or whenever you get hit to take an action, additionally, you have a Move of 1. You start making Death Tests when you get to -(Health) in HP.

OTHER FUNKY COMBAT RULES
Grappling
This is always a wonky set of rules in any game system. You roll to hit using HTH skill-- and then roll a Quick Contest of ST or DX (choice) versus ST or DX. Certain combat styles can give bonuses elements. If you keep your hold, then the target has their mobility and actions reduced. They can make another attempt to escape (another Contest) on their round.

If you keep a hold on someone, on the following round you can attempt to cause damage, attempt to bear the person down to increase the hold, or even throw the person. This requires a skill check. It is possible to grab and throw someone on the same action, but that requires an All-Out Attack action.

Hit Location
You can try to hit a specific location with an attack. Each location has a different penalty to hit. You can do extra damage depending on the area you hit. Called shots are all or nothing. Limbs can be disabled.

Criticals and Fumbles
You get a Critical Hit if you roll a 2 or a 3. If your skill is 14+, you Critical on a 4-. If your skill is a 16+, you Critical on a 5-. If your skill is a 18+, you Critical on a 6-. You can only defend against a Critical Hit by rolling a Critical Defense.

A Critical Hit allows you to make a roll on the Critical Hit table for additional effects. They're usually pretty cool.

A roll of a 19 or 20 is a Fumble. You can injure yourself...badly.

Disarming
To disarm, you make a standard attack, with a penalty for trying to hit the weapon (-4 to -6) depending on the size of the weapon. If you hit and the target does not defend, you make a Quick contest of Weapon Skill versus Weapon Skill. If the target loses, their weapon flies a yard away.