Enemy AI

Summary

In this video, Tim discusses key principles behind designing effective enemy AI in games. He emphasizes the importance of creating AI that is challenging, scalable, fair, and computationally efficient. The AI should provide a balanced challenge for players by being unpredictable yet logical in its actions. Scalability ensures that the AI remains relevant as the player progresses, while fairness focuses on avoiding unfair advantages for enemies. Finally, Tim explains how to optimize AI performance without sacrificing intelligence, using techniques like pre-scripted attack plans and cooldowns for complex calculations. This approach leads to engaging, responsive, and efficient enemy behavior.

Takeaways

• 😀 Enemy AI should be challenging, meaning it should provide a real threat to the player without being overly predictable or simple.
• 😀 The AI must feel fair to the player, avoiding any sense of 'cheating' by having information it shouldn't have, like always knowing the player's position.
• 😀 Scalability in enemy AI is important: it should evolve with the player's progression, allowing new abilities or tactics without needing to rewrite the AI.
• 😀 AI routines should be versatile enough to handle various in-game situations, such as taking cover or using group tactics.
• 😀 When designing AI, fairness means making the AI's actions understandable and logical, based on clues like sounds or visual cues from the environment.
• 😀 Challenging AI should require player skill, whether that's based on the player’s actions or the player's character's abilities.
• 😀 A well-designed AI should adapt to the player's actions and use new strategies, such as exploiting vulnerabilities in the player's defense or health.
• 😀 AI performance must be computable, meaning it shouldn't involve complex calculations every game tick, as this would impact game performance.
• 😀 Simpler AI routines, like predetermined attack plans or predefined behaviors, can make enemies more predictable and manageable for the player.
• 😀 Randomness in AI actions (e.g., randomizing enemy positions or attack precision) can make lower-level enemies seem more alive, providing a challenge without overwhelming the player.

Q & A

What are the four important traits to consider when designing enemy AI in video games?

The four important traits are: challenge, scalability, fairness, and computability. These factors ensure the AI provides a satisfying, efficient, and fair gameplay experience.

Why is it important for enemy AI to be challenging?

Challenging AI makes the game engaging by creating a sense of danger, requiring player skill to overcome enemies. This keeps the gameplay exciting and ensures enemies aren't too predictable or robotic.

What is the role of scalability in enemy AI design?

Scalability ensures that the AI adapts as the player advances in the game, without needing to rewrite it for each level. This allows enemies to remain challenging by adjusting their behavior, such as using new attacks or tactics.

How does fairness impact the design of enemy AI?

Fairness in AI means avoiding behavior that seems like cheating, such as enemies always knowing the player's location without reason. The AI should respond based on the player's actions in a way that feels natural and justified to the player.

What does 'computability' refer to in the context of enemy AI?

Computability refers to ensuring the AI can perform calculations within the time and space constraints of the game. Complex calculations can affect performance, so AI routines should be optimized to avoid lag or frame rate issues.

How can enemy AI be made more challenging without making it too complex?

Enemy AI can be made challenging by ensuring enemies have a chance to kill the player if left unchecked, using tactics like attacking when the player is distracted, and requiring player skill to defeat them. Complexity can be managed by using strategies like attack cooldowns and versatile routines.

What is the downside of giving low-level enemies too powerful items?

Giving low-level enemies powerful items, such as high-value armor or magic weapons, can break immersion and frustrate players. It disrupts the sense of progression and makes the game feel unfair.

How can enemy AI be scaled without rewriting it for every level?

AI can be scaled by adding new attacks, giving enemies new items or abilities, or using smarter AI routines that trigger based on the player's actions, such as using cover or group attacks. This ensures the AI remains challenging as the player levels up.

What are some ways to avoid AI 'cheating' in a game?

To avoid AI cheating, the game should make it clear that enemies are using clues to track the player, like responding to noise or changes in the environment. AI should not have knowledge of the player’s position unless the player has given it that information through their actions.

How can developers optimize enemy AI to reduce computational load?

Developers can optimize AI by using techniques like cooldowns to prevent repeated calculations, marking calculations as 'dirty' to be updated only when necessary, and using simpler routines based on the player's last known position rather than recalculating everything each tick.