Enemy Categorization

Enemy design is an important aspect of any game with combat. They provide important tests of player skill and game knowledge; the more varied they are, the more the game keeps things fresh. When designing the enemy roster for a game, beyond thinking of cool gimmicks for them, we need to think of what role they play in regards to the player and how they challenge them.

There are four roles enemies can fall under:

• Smashers — The weakest of enemies, their role is to make players feel powerful. They are generally simple, come in large groups and are easily taken care of. Ex.- goombas, small goblins and slimes.
• Emphasizers — These enemies are ones that incentivize the player to use one mechanic or strategy in order to deal with them. Crucially, players have the option to use other tools if they want to; it simply isn’t the most efficient way. As a rule of thumb for action/adventure games, most of your enemies should fall in this role. Ex.- Long Ranged Archers, Heavily Armored Soldiers, etc…
• Enforcers — These are more extreme than emphasizers, as they require the player to use a specific mechanic. We have to be careful when using them, as if a player hasn’t learned the skill/technique/strategy to deal with these, they will be stuck. That being said, they are great for making sure players learn a mechanic or for pushing the player outside of their comfort zone at high skill levels. Make sure the mechanic they use is glaringly obvious and that they are rare. Ex. An enemy that is only vulnerable to fire attacks.
• Challengers — These are the strongest of the enemies, generally mini-boss and bosses. They require players to understand multiple game mechanics and execute them well. They generally have high stats, complex behaviors and multiple attacks. Generally they are used sparingly. Ex. All bosses in a game 😛

Enemies can also be divided up by Tier. Tiers refer to the expected difficulty of the enemy and how they rank up compared to other enemies. This is really useful to make sure that every stage of a player journey (from beginner to elder) has enough enemies to keep things challenging and interesting. Although it’s tempting to shove all the Challengers into the highest tier, remember that tiers are meant to be relevant to the player strength. It is not uncommon for a tier 1 Challenger to be weaker than a tier 5 Enforcer.

Finally a note on gimmicks that I mentioned up top. A gimmick is what makes a specific enemy special; i.e. why does this one have to be in the game. It should be easy to explain in a sentence. Another way of thinking of it (suggested by Mike Birkhead) is “What is this guy’s trick?” Using a variety matrix is a good way to answer these.

This categorization comes from God Of War designer Mike Birkhead in his blog post How To Design Enemies: Tips From A Combat Designer  (sadly the article doesn’t seem to be online anymore). Bart Vossen also talks about it in Enemy design and enemy AI for melee combat systems.

1. Have an initial brainstorm of enemies
2. Make a grid where you have the tiers on one axis and the roles on the other.
3. Fit your enemies into each category.

Be on the lookout for clusters (categories with lots of enemies) and gaps (categories with almost no enemies). These are not necessarily wrong, but they must be a conscientious decision. For an action/adventure game, enemy numbers would be: Emphasizers > Challengers > Smashers > Enforcers; they would also be more numerous in lower tiers. These rules of thumb will change depending on the game genre (for example Bullet heavens are practically all smashers), the game’s player journey (gentler curves have more lower tiers) and target audience (games built for a large and experienced elder player base tend to have more challengers and higher tier enemies).

Let’s imagine that we are a 2D side-scrolling brawler in the same vein as Streets Of Rage

In true arcade style, we want the game to be hard throughout (so players use up more quarters). This means that the first level might be a bit easier, but the difficulty will spike from there. Few players, if any, will reach the end. With this in mind, after listing out all the enemies in the game, our grid might look like this:

There are some clusters in tier 2 and some gaps in tier 1; however, as stated above, we are not as concerned with beginner players and we don’t expect many players to reach the end. With that in mind, the clusters and gaps have been deemed acceptable.

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