Role Playing Games (RPGs)

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Role Playing Games (RPGs). Mike Rowan Anthony Scimeca. Overview. History Tactics MMORPG Large Scale AI Reputation System Side-Quests. Overview. Games which are typically set in a fantasy environment. (Magic, Mythology, etc.) Top Down View - PowerPoint PPT Presentation

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Role Playing Games (RPGs)

Role Playing Games (RPGs)Mike RowanAnthony ScimecaHistory TacticsMMORPGLarge Scale AIReputation SystemSide-QuestsOverviewGames which are typically set in a fantasy environment. (Magic, Mythology, etc.)Top Down View Rich and extensive stories to entertain user.Strategic element to gameplay.Heavily built on character building.Use of Hit Points (HP) for health.OverviewRPGs are a hard genre to define and are ultimately descendants from a wide variety of games.War games, Sports Simulation, etc.Dungeons & Dragons (1974) board game that revolutionized the genre and can almost be considered a prototype of later RPGs.Fantasy based game where users used imaginations to depict a world of possibilities combination of make-believe, play-acting, and a logical, math-based rule system.HistoryDND (1974) first CRPG (Computer RPG) Made for PLATO (a computerized learning system at Southern Illinois University)Game consisted of many novels of RPG genre such as character creation and development of specific statistics, and leveling up with experience points. Featured a shop to buy equipment.Story involved killing a dragon and obtaining orb.History

UNIX based games helped pave the way for common day RPGs.Rouge (1980) Featured randomized dungeons for replay ability.Ultima (1981) laid many foundations such as tile based graphics, and more complex fights requiring more strategyWizardry: Proving Grounds of the Mad Overworld(1981) First RPG that was party-based, offered first-person view of action.HistoryTurn basedEach member of party has a turn and can perform an action at this time.Slower pace to allow for user to think things outWizardry video (1:10-2:31)Real-TimeMore realistic, fast-paced.Can get hectic with needing to keep track of many things at once.Chinese game Qingcheng videoCombatNeed path finding algorithms for enemy NPCs in todays games.Have more difficult AI in later stages of game. Need smart AI for friendly NPCs and enemy NPCs.Must quickly assess situation and decide what is best tactic to use.Consider strengths/weaknesses of party members on each side.Pokemon (1:45-2:05)Heroes of Might and Magic (1:40-2:10)AIMMORPGMassively Multiplayer Online Role Playing GamePopular MMORPG games include EVE Online, World of Warcraft, Aion, Guild WarsMany are pay to play and do not offer a simple You Win or Game Over screen, no matter how long you playMMORPG Player InteractionPlayers can interact with most players usually based upon other player localityFor example, a player can speak something that will show up on the chat screen of other players within 25 yards or a player can yell something that has a 100 yard radiusOther players follow the same rules as the player, however they interact at their own pace, not controlled by the CPUMMORPG Reputation SystemThe reputation system is one of the biggest drivers of player environment interactionSome reputations determine who the player fights and who the player can interact friendly towardsThe player needs a sense of involvement with the NPCs in an MMORPG because the player wants to interact with their environment as they do different thingsMMORPG NPC UnitsThe AI is very important in NPC unitsPath finding to various players and player set obstaclesAnalyzing the reputation of other playersPriority system for determining who to attack or defend, also known as threat or aggroPath findingAI units in MMORPGs need to be able to find the player (or multiple players) from any location and learn how to get there or otherwise compensate for the situation

Threat / AggroThere are numerous ways enemies can attack another player when there are multiple players playing the gameAttack at randomAttack first on sightAttack strategically depending on the players rolesThere are modifiers that exist to change thisThreat / AggroFor example, a unit may have a specific ability to force the unit to attack it by shielding friendly targets or putting themselves on top of the priority list of potential targetsA good example is in World of Warcraft. A tank unit is designed to direct all damage to it by using abilities that have high threat

Threat / AggroAs threat is generated, the enemy keeps a list of who is generating the most threat. That will determine who they will attack

With the emergence of MMORPGs and the large sizes that are demanded out of RPG games today, larger maps are needed, meaning more NPCs are interacting at a certain time.To compensate for this issue, a concept of Level of Detail AI is used. The following is the implementation used for Neverwinter Nights (NWN) by BioWare. Level of Detail AIConcept is borrowed from graphic engines.Essentially, objects that are further in the distance do not need to be made as complex so they are constructed with less polygons.Level of Detail AI

To translate this into an AI perspective, NPCs that are out of the viewing distance from the human player do not need to be fully processed and optimized.Need to split characters into groups according to distance.Level of Detail AILevel of Detail AI

Level of Detail AI

Assign a certain % of CPU time to each category. Will determine how much CPU is devoted to specific group every iteration of an update.Level of Detail AI

Levels 1-3: go through the entire pathfinding algorithm, since these characters are shown their movements need to be smooth and natural.Level 4: Characters are out of viewing range, they perform inter-tile method but instead of smooth movement, they jump from tile to tile.Level 5: Characters are not in vicinity, therefore simply determine time between itself and destination, then have a delay and jump to target locationLevel of Detail AI - PathfindingNWN has very complex rule set, the Basic combat rules fill 10 pages of text and there are over 50 pages of exceptions to the base rules.Therefore need to cut down processing power used in each combat situation, especially when not shown.

Level of Detail AI - CombatLevel 1&2: Implement full rule system since combat is actively shown to user.Level 3: Implement full rule system unless many complications occur. If this is the case, skip computations, need to allow character to look like it is performing correct action.Level 4: Compute each characters damage capabilities and determine winner through formula. (Level 5: Perform biased coin flip according to damage capability of each character.Level of Detail AI - CombatReputation SystemProvides a different system of events for players who want an alternative playing experienceShows the player that the AI controlled factions care about what you do for them, making the player feel involvedAllows the player to strive for things, such as rarities and rewards specific to a particular factionMaster Event ListSo, are all events stored per NPC?Events are stored in a Master Event ListConserves memoryKeeps events organized for more timely responseEasy to updateEvents are consolidated so that an NPC can reference the list in order to determine how they should react to the player instead of keeping their stance in local memoryMaster Event ListTo add an event to the list, you take an event:

Subject GroupPlayerVerbDidViolenceToObject GroupBanditObject IndividualJoeMagnitude75 (Killed)Where50,20,138 (in front of saloon)WhenHigh NoonTemplateKilledBanditTemplateReference CountKnown by 11 NPCsReputation EffectsBandits hate player moreLawmen like player moreFarmers like player moreProvide a table entry with the details:Master Event ListLater on, the NPC can reference that listNPCs can share information between themselves if they find it relevant about the player so reputation can trickle down to all NPCs associatedThis gives the programmer the ability to change the gameplay for the player based upon previous player choicesFaction KnowledgeNow we see how these events can occur, how can an NPC remember?Assign a hierarchy of reputationFor example, if someone helped or hurt someone from Lehigh, that may affect you. If this someone was also a family member, it would affect you moreThe following example from EVE on the trickling down of reputation

Agent works for Federation Navy

This agent is Level 1

This players current standing (reputation) is 6.4

Mission named Break Their Will

Upon mission completion, player receives 0.1389% reputation gain for Federation Navy

This players new standing with the agent is 6.5

The player gained some reputation

Reputation allows for many things:Access to higher level agents that give better rewards.Ability to purchase better itemsAdditional servicesUpon completion of a Level 4 mission, there are higher rewards than a Level 1For example, notice the higher gain in reputation towards the Navy

Optional missions that involve objective based storylines that are separate from main storyline.Normally used to obtain a useful item, gain extra experience, or learn more about the overall story or background of game.Allows gamers to make decisions in story, and makes getting a 100% completion rate a more difficult and rewarding task. Zelda SatireSide QuestsSide QUEst GEnerator Tool software for generating side quests, reduce manual labor in creating them.Programmer can then write dialogue for quest after generating or hook SQUEGE up to a game dependent script generator Have specific patterns for side quests.Assassains CreedSQUEGEPatternDescriptionTalk ChainTalk to multiple NPCsAcquire itemFind location of item and obtainDeliver itemFind location of item and return to an NPCKill antagonistFind location of NPC and killAssassinate antagonistFind location of NPC and kill then report back to NPC who assigned missionOne of many tasksMust complete one of several tasksAll of many tasksMust complete all tasks specifiedChain questComplete pattern one after another in s