There are three fundamental questions at the heart of designing enemies for an action game. The first is:
1. How will this enemy force the player to react?
Any enemy can be tuned to be deadly. In fact, overly lethal enemies are often a symptom of a poorly balanced game; nobody enjoys being flattened by an unstoppable steamroller. And any enemy can be crippled until it is merely a target in a shooting gallery. When a designer has run out of ideas for making an enemy fun, the fallback position is usually “bullet sponge”. The key to designing an enjoyable opponent for the player is finding a way to split the difference — forcing the player to react to an enemy without resorting to killing them.
To achieve this, it is important for the enemies to take the initiative and make the first move. Players will tend to repeat the same tactics over and over if they continue to work. By preempting their default strategy the enemy will challenge them to improvise, to think more strategically, or to experiment with new tactics.
- Disarm the player, or prevent them from using their primary attack
- Invade the player’s space, requiring them to start a fight before they are ready
- Use a special non-lethal attack that stuns or knocks the player around, preventing them from fighting back until they can counter it
Another good way to force the player to react beyond taking and dealing damage, especially in shooters, is to force them to move. By making the player aware of their environment — the connectivity of the space and their physical relationship to their surroundings — a well-designed enemy can greatly increase the strategic depth of combat.
- Attack from a range that is outside or inside the player’s optimal range
- Deny the player use of an area (as with a long-fused grenade) forcing them to move to a different area
- Take cover behind an object, requiring the player to switch positions and flank them
- Charge to melee range, so the player must retreat or change weapons
Another way the player can be made to react is by changing something significant about the fight so they have to re-prioritize their targets or switch tactics. This change doesn’t have to be immediately dangerous, it just needs to tilt the battlefield in a new direction.
- Begin a devastating attack with a long wind-up that can be interrupted
- Perform an attack that ends in a temporary vulnerability that the player will want to exploit
- Allow the player’s current target to quickly withdraw or become invulnerable, removing themselves from the fight temporarily
Another tool for causing a reaction that is often overlooked is dialog or dramatic behaviors that don’t serve a combat function, but can still influence the player and cause a reaction.
- Taunt or mock the player to incite anger
- Announce an upcoming action (like reloading) to draw the player’s attention
- Threaten or attack one of the player’s allies, giving them a chance to be a hero
Far from being a secondary concern to be considered after an enemy can already fight well, these non-lethal interactions with the player should be designed first and receive the most attention. Once the player is engaging an enemy with their mind — and not just their fingers and their weapons — they will be having fun. At that point it is easy to make them more or less lethal as the balance requires.