This new series of blog posts will be based on /r/roguelikedev FAQ Fridays, a long standing series of discussions where roguelike developers share their techniques and experiences around a single topic.
How do you decide what mobs/items/abilities/terrain/etc to add to your game? In any good roguelike content creation is inseparable from the concept of balance, so your methods of balancing content are certainly within the scope of this discussion.
Ananias has a fairly static collections of monster races. They were first added based on the original rogue monsters and with a single criteria on mind: each race should have an unique feature or ability.
Sometimes implementing an ability is costly and there’s the temptation of parameterizing it so it can be reused with slight variations, but I think it gives more character to the monsters having their distinctive skills. This means Ananias doesn’t have Ice, Fire, Water, Earth and Thunder dragons whose only distinction is the “type” of their attacks, I’d rather have a single Dragon monster distinguished by a strong ranged attack.
The uniqueness of an enemy race is not defined only by their active skills, their stats are also put in consideration. In this case they are assigned relative values first (i.e. orcs have high attack and medium hp, Lizardmen have extreme high attack and low hp). This is balanced so that races without cool active skills get some advantage stats-wise.
The dungeon is then split into 5 areas with increasing difficulty. Mob races are grouped thematically on these areas and then assigned final values for their stats by scaling their relative values to the difficulty level of the group they are in. In order to do this, I do a projection of the average stats for the player on each one of these areas and then I apply some simple general rules (for example, a strong monster may kill the player in 5 hits, a monster with low HP should be killed by the player in a single attack). These define ranges within which the stats of the final monster will be placed.
Items follow a similar model. For weapons and armor I started with a list of preexisting graphics (the artist made them on advance for a different game using his own creative criteria) then based on they appearance I assigned them relative values (high/mid/low) for damage and integrity (how likely they are to break), and then I grouped them on power tiers to define their final stats. They also get assigned a generation weight representing how likely they are to be added to the levels, this value is used in level generation along with the power tier to select the items to be added.
Player abilities are guided by the same principles of uniqueness. Ananias is strongly classed, and each class has unique passive skills that guide players into adapting different playstyles for each one. The process for player classes is similar as with the monster races, they are balanced based on their skills and relative values for their stats. (Except for the shepherd ;)).
On a final note, I’d like to say that while seeking to balance the different stats is worthwhile (to prevent your game from being utterly broken), it’s also to some point a futile exercise, since the variability of the game and the player’s choices create a lot of unpredictability, specially as journeys progress in games which provide long and open experiences. This is not necessarily a bad thing, and a little bit of unbalance is not always harmless since it allows the players to find strategies and challenges within the game.