The Game, MagePowerCraft

The gaming environments is built up by using OGRE3D [OGR11] which is one of the most popular open-source graphics rendering engines. The 3D models are texture-mapped and rendered on the screen. The library, Hikari, is adopted for using the fancy flash GUIs in OGRE3D environment. Figure 5.2 shows the snapshots taken inside MagePowerCraft.

5.1.1 Game Rules

MagePowerCraft is a regular team-combating game much like the team player-killing (PK) systems of most modern multiplayer online action role-playing games. It supports up to a maximum of 3-on-3 team combating inside an arena. The rules of MagePowerCraft are clear:

1. The team which defeats all the opponents of the other team will score one point.

Figure 5.1: Snapshots taken from the game MagePowerCraft

2. If no team is defeated within the time limit of a match, then the match is drawn and each team is rewarded with a score of one.

3. A character is defeated once its health point (HP) reaches zero.

After a number of team battles are over, the team with the higher point would be regarded as more powerful than the other team.

5.1.2 Game Character Classes and Skills

Figure 5.2: The four character classes of MagePowerCraft. From the left to the right are the Fire Wizard, the Ice Wizard, the Priest and the Shaman.

There are four classes of characters in MagePowerCraft, they are the Fire Wizard, the Ice Wizard, the Priest and the Shaman as shown in Figure 5.2. While combating, the hair colour of the characters will be changed to their team colour, red for team 1 and blue for team 2 as demonstrated in Figure 5.3. In this manner, the observers may differentiate both teams more easily. Each character class has four different skills. Although this is an in-house created game, the skills of MagePowerCraft are all rich designed. The settings of a skill may be attributed as an aiding or an attacking skill to single or multiple targets.

A skill can be cast on either friendly or hostile targets.

Figure 5.3: The hair of the characters will change to their team colour. Red for team 1 and blue for team 2.

Figure 5.4: The three area of skill effect types.

There are attributes of the skills which include the power setting of the skill, area of effect (AOE) types, maximum hit, casting time, cost of mana power (MP) per cast, the cooldown (CD) time and also the special effects. The power setting of a skill includes parameters as SkillP ower and SkillExtraP t which affect the power of the skill. The three AOE types in MagePowerCraft as shown in Figure 5.4. AOE Type I is Self-Centered, the skills of this type will effect on the area centered by the caster. Type II is Front-Field, where this kind of skills will make influence to the circular/fan area in front of the caster.

And Type III is Front-Rectangular that the effecting area is a rectangular field in front of the caster. Each of the AOE type has its own parameters for creating more variations of the effects. The maximum hit of a skill indicates the maximum number of hit that a skill might cause to its target per cast. Casting time determines the time needed for casting a skill before it takes effect. Cost of MP is the amount of MP needed for each cast of the skill. CD time defines the period of wait time before a skill can be used after a prior cast of the skill. The special effects of a skill may bring different buffing (positive) or de-buffing (negative) status to the targets as shown in Table 5.1. Please check Appendix A for the detail settings of all skills of the four character classes.

Other than the various settings of the skills, all other attributes such as total HP, total MP, magical attack power and etc. of the four character classes are the same. The settings of the attributes of the four classes are listed in Table 5.2. In this way, we can focus on investigating the method for evaluating the fairness of the power of skills in MagePower-Craft using TABS.

5.1.3 Attack and Defense Formulae

A skill may cause several aiding/damage hits to its targets. The magical power of a character for each hit is computed by:

M agicP ower = AttackP tmin + r₃(AttackP t_max− AttackP tmin), (5.1)

where AttackP t_minand AttackP t_maxare the minimum and maximum of the magical

Skill Special Effect Description

Powering Up Enhances the Magical Attack Power of its target for a while.

Regenerating

Keeps on increasing the HP of its target periodically over a certain duration.

Burning

Keeps on deducing the HP of its target periodically over a certain duration.

Frostbiting Slows down the movement speed of its target.

Electrocuting

Stops any action of its target intermittently over a certain duration.

Freezing

Makes its target temporarily immobilized for a while and interrupt the spells being cast by the target.

Stunning

Makes its target temporarily immobilized for a while and interrupt the spells being cast by the target.

Stunning

Makes its target temporarily immobilized for a while and interrupt the spells being cast by the target.

Poisoning

Keeps on deducing the HP of its target periodically over a certain duration.

Table 5.1: Skill Special Effects and their descriptions.

power of the caster, and r3is a random value inside [0, 1]. The amount of damage per hit, DamageP t, is given by:

DamageP t = max(0, M agicP ower× SkillP ower + SkillExtraP t − DefenseP t), (5.2) where SkillP ower and SkillExtraP t are the Skill Power and Skill Extra Point, which are the parameters of the skill, and Def enseP t is the current defense power of the target. The total damage of the skill is DamageP t× HitNum, where HitNum is the actual hit number taking effect to the target. HitN um is affected by T argetT oEmit, which is the distance between the target and the skill emitting point/line. The computation

HP MP Basic Magical Attack Magical Attack Magical Mana Moving MP Power (Min) Power (Max) Defense Recovery Rate Speed

20143 20836 6840 1642 1715 2875 0.585% 2.3529 m/sec

Table 5.2: Character attributes of all classes in MagePowerCraft.

of HitN um is given in Equation 5.3 and 5.4, where M axHit is the maximun hit number of the skill, Radius is the radius of area of effect type II, F arClipDist and N earClipDist are the far and near clip distance of the skill.

HitN um =⌊M axHit× (SkillRange − T argetT oEmit)

Radius if the skill is area of effect type II, F arClipDist− NearClipDist otherwise.

(5.4) For the healing skills, such as the Heal of the Priest and the Life Charge of the Shaman, the SkillP ower is directly applied to the maximum HP of its target, M axHP . Thus, the healing points per hit, HealP t is given as:

HealP t = M axHP × SkillP ower + SkillExtraP t (5.5)