StendhalDesign: Difference between revisions

This small doc tries to create an agreement on what stendhal is about and what it needs to include. It considers the existing [[StendhalObjectives#Roadmap Roadmap|]] and tries to give a coherent vision of what we are trying to create.

Our world is made of several entities: players, wolves, rats, sheeps, NPC. By describing each entity with use cases we will simplify later the coding stage.

Seller says "Do you want to sell your Sheep for <estimated price> coins?"

set Player XP=Player XP + 100 * Sheep Weight / 100

===Rat's user case===

Rat and Cave rats are creatures that will attack player to make it harder to grow the sheep up.

<pre>

Rat moves

If Rat sees Player:

Rat attacks Player

If Rat is attacked:

Rat attacks Attacker

</pre>

* Rat

* Cave rat

* <b>x</b> is the x-position of the sheep

* <b>y</b> is the y-position of the sheep

* <b>dx</b> is the x-speed of the sheep

* <b>dy</b> is the y-speed of the sheep

* <b>hp</b> is the life indicator of the sheep, when it reach 0 the sheep dies.

* <b>atk</b> is the RP attack value. See [[StendhalDesign#RP|RP rules]]

* <b>def</b> is the RP defense value. See [[StendhalDesign#RP|RP rules]]

* <b>xp</b> is the RP experience value. See [[StendhalDesign#RP|RP rules]]

* <b>weight</b> is the weight indicator of the sheep, the more weight, the more expensive it is.

* <b>follow</b>

* <b>eat</b>

Sheep will runaway if attacked.<br>

=== Creatures: Wolf, rat and Cave rat ===

Wolves, rats and cave rats have the following set of attributes:

* <b>x</b> is the x-position of the wolf

* <b>y</b> is the y-position of the wolf

* <b>dx</b> is the x-speed of the wolf

* <b>dy</b> is the y-speed of the wolf

* <b>hp</b> is the life indicator of the wolf, when it reach 0 the wolf dies.

* <b>atk</b> is the RP attack value. See [[StendhalDesign#RP|RP rules]]

* <b>def</b> is the RP defense value. See [[StendhalDesign#RP|RP rules]]

* <b>xp</b> is the RP experience value. See [[StendhalDesign#RP|RP rules]]

Wolf ( and rat and cave rat ) tasks should be:

* <b>follow</b> means that wolf follows an object using the shortest way to reach it.

* <b>attack</b> means that wolf will try to damage the attacked object until its hp reach 0<br>Another action will cancel attack task.

* <b>patrol</b> means that wolf will move around a specified path.

* <b>chat</b> means that wolf will start to shout 'auuuuuuu!'. Wolves will often understand this as a call.

Wolf ( and rat and cave rat ) behaviour consists of patrolling some assigned areas.<br>

If the Wolf finds a Player, it will attack player.<br>

If the Wolf is severly injured, the Wolf will runaway.<br>

=== Sheep seller, Sheep buyer, Beggar ===

* <b>x</b> is the x-position of the NPC

* <b>y</b> is the y-position of the NPC

* <b>dx</b> is the x-speed of the NPC

* <b>dy</b> is the y-speed of the NPC

* <b>hp</b> is the life indicator of the NPC, when it reach 0 it is reset back to full.

* <b>atk</b> is the RP attack value. See [[StendhalDesign#RP|RP rules]]

* <b>def</b> is the RP defense value. See [[StendhalDesign#RP|RP rules]]

* <b>xp</b> is the RP experience value. See [[StendhalDesign#RP|RP rules]]

* <b>attending</b> is the object_id of the player that is actually attending.

seller, buyer and beggar tasks would be:

* <b>patrol</b> means that NPC will move around a specified path.

* <b>x</b> is the x-position of the player

* <b>y</b> is the y-position of the player

* <b>dx</b> is the x-speed of the player

* <b>dy</b> is the y-speed of the player

* <b>hp</b> is the life indicator of the Player, when it reach 0 the player dies. See [[StendhalDesign#Dead|Dead]]

* <b>atk</b> is the RP attack value. See [[StendhalDesign#RP|RP rules]]

* <b>def</b> is the RP defense value. See [[StendhalDesign#RP|RP rules]]

* <b>xp</b> is the RP experience value. See [[StendhalDesign#RP|RP rules]]

* <b>money</b> is the quantity of money the player has.

* left hand

* right hand

* <b>move</b> means that player will change its dx, dy params to move.

* <b>attack</b> means that player will try to damage the attacked object until its hp reach 0.<br>Another action will cancel attack task.

* <b>chat</b> means that player writes text to other players or NPCs

* <b>x</b> is the x-position of the player

* <b>y</b> is the y-position of the player

* <b>quantity</b> is the amount of food available

=== Armor ===

Armor is an item that player can ''wear'':

* <b>x</b> is the x-position of the armor when player doesn't wear it.

* <b>y</b> is the y-position of the armor when player doesn't wear it.

* <b>def</b> is the RP defense value. See [[StendhalDesign#RP|RP rules]]

* <b>weight</b> is the weight of the armor.

=== Shield ===

Shield is an item that player can ''wear'':

* <b>x</b> is the x-position of the shield when player doesn't wear it.

* <b>y</b> is the y-position of the shield when player doesn't wear it.

* <b>def</b> is the RP defense value. See [[StendhalDesign#RP|RP rules]]

* <b>weight</b> is the weight of the shield.

=== Weapon ===

Weapon is an item that player can ''wear'':

* <b>x</b> is the x-position of the weapon when player doesn't wear it.

* <b>y</b> is the y-position of the weapon when player doesn't wear it.

* <b>atk</b> is the RP attack value. See [[StendhalDesign#RP|RP rules]]

* <b>weight</b> is the weight of the weapon.

=== Healing potion ===

Healing potion is an item that player can ''wear'' inside the backpack:

* <b>x</b> is the x-position of the potion when player doesn't wear it.

* <b>y</b> is the y-position of the potion when player doesn't wear it.

* <b>heal</b> is the amount of HP the potion will heal.

== Actions ==

The key on making Stendhal moving is to add actions.

As we have seen each entity has a list of actions that can do. Let's see them and study they interact.

===Player===

Our main entity is Player, it is gamer's avatar in stendhal world and as such, it is able to do the next set of actions:

====Move====

Move action can be understand as two actions:

Move to left,right,up or down while key is down<br>This action allows controlling gamer's avatar using our keyboard that is the arcade/adventure game style like Nintendo Zelda.

This action should have the next set of attributes:

* '''dx''' horizontal speed of the avatar

* '''dy''' vertical speed of the avatar

We can have as many as we want of this action. The last action executed will be the only one that alters really dx and dy.

====Move to a position====

This action allows controlling game's avatar using a mouse, so we can click ( or double click ) to move to the position where the mouse clicked. This mode is great for a more relaxed adventure game style like Bioware Baldur's Gate.

This action should have the next set of attributes:

* '''x''' desired x coordinate of the avatar

* '''y''' desired y coordinate of the avatar

We can only have ONE action of this type and only the latest one will be considered valid. This action is cancelled by any other action like Move, Attack, Face, ...

Both move actions will have at each end of turn, moving the avatar if it is possible dx units in the x axis and dy units in the y axis.

If avatar collides with something while moving, dx and dy will become 0.

====Face====

This action is useful as a extra for the social side of the game; when you are talking it is often good to ''face'' the person you are talking too. So face action allows our character to look at the direction we tell it: left, right, up or down.

====Chat====

This action is the base of any social game like a MORPG.

This action should have the next set of attributes:

* '''text''' text that the player is going to say

Due to Arianne framework it is not possible to create a yell or whisper action, when you talk, you talk for everybody in the area, that is why area design is *VERY* important to achieve a good gameplay.

====Attack====

This action is the core of the gameplay for lots of gamers to consider the game fun. All the combat is ruled by the RP game system explained in the RP section of this page.

There are some limitations for combat right now:

* No PvP ( Player versus Player )

* Can't attack yourself

* Can't attack NPC

We want to preserve a nice game experience so we have removed player vs player combat.

We can have only ONE attack action, so choose wisely your target, and this action is cancelled by any other action but '''Chat''' and '''Heal'''.

This action should have the next set of attributes:

* '''target''' the object.ID of the player that we are attacking.

This action require that the target of the action is ''near'' our avatar. Near means that target's avatar have to be colliding with our avatar.

The attack action has the implicit meaning of following the target.

====Equipment and Inventory====

This action is very important as it handles most of the complexity and the fun of a RPG: getting new stuff and use items to solve quests.

'''TODO'''

=RP=

Role playing games are based in a set of rules. There are many set of rules: AD&D, GURPS, Warhammer,...<br>

Stendhal defines a new ''typical'' set of rules, that has in common simplicity and ease of computing.

The system is based around 3 ideas:

* Randomness using 1D6

* Risk evaluation

* Creativity

Risk evaluation gives the DM the power to weight up an action that a player wishes to perform against things like how experienced the player is in that type of action and the situation the player is in.

DM stands for ''Dungeon Master''. In Stendhal our task is to design the DM, as it rules the game.

== Attributes ==

Each player has a set of attributes that are:

* <b>attack</b> - this value is used to resolve attack situations.

* <b>defense</b> - this value is used to resolve situations where the player is attacked.

* <b>hp</b> - this value stored the live points available.

* <b>level</b> - this starts off as zero when the character is created and will increase related to experience

* <b>experience</b> - this is the amount of experience gained at the current level

===Entity Attribute values===

The hardest part of any RP is to give balance to the values different entities has.

We need to give RP(atk, def and hp) values to:

====Player====

Let's make our starting player to be:

* <b>ATK</b> - 2

* <b>DEF</b> - 2

* <b>HP</b> - 100

These values have been set randomly.

====Sheep====

A sheep can't attack, so it has to be weaker than player.

* <b>ATK</b> - 0

* <b>DEF</b> - 1

* <b>HP</b> - 30

These values have alse been set randomly according to player values.

Killing a sheep won't report you any experience.

====Rat====

A rat is the simplest enemy you can find in Stendhal, so it has to be simple enought for a Level 1 player to kill.

* <b>ATK</b> - 3

* <b>DEF</b> - 2

* <b>XP</b> - 5

* <b>HP</b> - 10

To set these values we have run a simulation until we have get the right look in the graphs.<br>

http://arianne.sourceforge.net/wiki_images/rat.gif

====Cave Rat====

A cave rat is a stronger version of a rat, so it has to be simple enought for a Level 2-3 player to kill.

* <b>ATK</b> - 6

* <b>DEF</b> - 2

* <b>XP</b> - 10

* <b>HP</b> - 20

To set these values we have run a simulation until we have get the right look in the graphs.<br>

http://arianne.sourceforge.net/wiki_images/caverat.gif

====Wolf====

A wolf is a common creature on plains and forest, it has to be simple enought for a Level 4-5 player to kill.

* <b>ATK</b> - 6

* <b>DEF</b> - 4

* <b>XP</b> - 18

* <b>HP</b> - 35

To set these values we have run a simulation until we have get the right look in the graphs.<br>

http://arianne.sourceforge.net/wiki_images/wolf.gif

== Experience and levels ==

All of the attributes can be increased during the game through gaining experience and levels.

Experience is awarded by DM for several reasons:

* good roleplaying

* use of skills

* combats

Experience can't be gained by training.

When you gain a level you can increase one of the attributes.

To reach a level you need to reach the next experience points:

<table border=1 align=center>

<tr bgcolor=black><td><font color=white>Level</font></td><td><font color=white>Experience needed</font></td><td>HP value</td></tr>

<tr><td>0</td><td>0</td><td>100</td></tr>

<tr><td>1</td><td>100</td><td>110</td></tr>

<tr><td>2</td><td>128</td><td>120</td></tr>

<tr><td>3</td><td>384</td><td>130</td></tr>

<tr><td>4</td><td>768</td><td>140</td></tr>

<tr><td>5</td><td>1408</td><td>150</td></tr>

<tr><td>6</td><td>2432</td><td>160</td></tr>

<tr><td>7</td><td>3712</td><td>170</td></tr>

<tr><td>8</td><td>5504</td><td>180</td></tr>

<tr><td>9</td><td>7808</td><td>190</td></tr>

<tr><td>10</td><td>10624</td><td>200</td></tr>

</table>

As you can deduce the HP grows at a rate of 10 per level, and ATK and DEF values are increased one on each new level.

The formula to calculate XP is:

exp = (10*level+5*level^2+10*level^3+80)

== Combat ==

Combat is a fight between two or more players.

The combat is round based. Each round takes 5 turns.

The risk to strike a player can be written as:

<pre>

Attacker.attack VS Defender.defense/6 + 1D6

</pre>

If player is hit we need to compute the wound that has been done:

<pre>

result = Attacker.attack/6 + 1D6 VS Defender.defense

if result > 0:

Defender.hp = Defender.hp - result

end if

</pre>

Death happens when hp reachs 0.

A critical hit happens when both die rolls are 6. And the damage is equal to Attacker.attack

===Shields===

The shield rating adds to your defense skill:

<table border=1 align=center>

<tr bgcolor=black><td><font color=white>Shield</font></td><td><font color=white>Rating</font></td></tr>

<tr><td>Buckler shield</td><td>+1</td></tr>

<tr><td>Small shield</td><td>+2</td></tr>

<tr><td>Medium shield</td><td>+3</td></tr>

<tr><td>Large shield</td><td>+4</td></tr>

<tr><td>Tower shield</td><td>+5</td></tr>

<tr><td>Green Scale shield</td><td>+6</td></tr>

<tr><td>Black Scale shield</td><td>+7</td></tr>

</table>

* black/green scale shields are dropped from the black/green dragon.

===Armour===

Armour helps you absorb damage.

<table border=1 align=center>

<tr bgcolor=black><td><font color=white>Armour</font></td><td><font color=white>Rating</font></td></tr>

<tr><td>Leather armour</td><td>+1</td></tr>

<tr><td>Studded leather armour</td><td>+2</td></tr>

<tr><td>Scale mail armour</td><td>+3</td></tr>

<tr><td>Chain mail armour</td><td>+4</td></tr>

<tr><td>Plate mail armour</td><td>+5</td></tr>

<tr><td>Field plate armour</td><td>+6</td></tr>

<tr><td>Full plate armour</td><td>+7</td></tr>

<tr><td>Green Scaled armour</td><td>+8</td></tr>

<tr><td>Black Scaled armour</td><td>+9</td></tr>

</table>

* black/green scaled armour are dropped from the black/green dragon.

===Weapon===

Weapon helps you to kill :)

<table border=1 align=center>

<tr bgcolor=black><td><font color=white>Weapon</font></td><td><font color=white>Rating</font></td></tr>

<tr><td>Knife</td><td>+2</td></tr>

<tr><td>Club</td><td>+3</td></tr>

<tr><td>Spear</td><td>+4</td></tr>

<tr><td>Axe</td><td>+5</td></tr>

<tr><td>Long sword</td><td>+6</td></tr>

<tr><td>Two hand sword</td><td>+7</td></tr>

<tr><td>Green Scaled sword</td><td>+8</td></tr>

<tr><td>Black Scaled sword</td><td>+9</td></tr>

</table>

* black/green scaled swords are dropped from the black/green dragon.

== Dead ==

The result of combat is usually dead.

When you kill a creature a corpse will appear. If you open it, you will be able to get whatever it has inside, usually food, gold, weapons, shields or armors.<br>

Each time you kill a monster you are rewarded XP.

When you are killed you reappear on city and you lose your sheep if you have one.<br>

Also to penalize dead, you are remove 10% of exp points and if it is the case you are removed HP, ATK and DEF increases because of level up.