Monday, 23 June 2008

Designing a Magic System - Part Five (Effects: Resets, Keys and others)

(You'll probably want to read parts one, two, three and four before starting this).

3. Resets

Problem: The player can end up in many inescapable situations in game without necessarily realizing it - the game over maybe minutes or even hours down the track, but because the player is still alive, they continue playing even though they do not have the necessary means to finish the game. This may be because the player is suffering too much attrition to their hit points because they are not playing well enough in each encounter against an enemy, or they have failed to master the necessary steps required to avoid a lock or trap.

Solution: Provide the player with a collection of resets, instead of having a single exhaustible resource that is slowly diminished. A reset sets some or all of the player state to its original values, or deletes or removes part of the environment, so that it is no longer an insurmountable obstacle.

In addition to providing resets, the designer should reduce the overall player resources, such as hit points to a much lower level than required to complete the game. This has the effect of letting the player know that they are in trouble and need to improve their game play, much earlier than a huge single health bar would do. Management of the resets becomes an important part of playing the game.

For example, in Angband, the player will suffer many tens of thousands of hit points worth of damage over the game. But starting the player with tens of thousands of hit points will mean that they can progress a long way through the game without necessarily learning the 'correct' skills required to play. By reducing the overall hit points and making management of healing potions and resting important game requirements, the player is forewarned that they have not mastered the game intricacies. (This forewarning takes the form of premature death.)

Resets contribute to avoiding a 'death by a thousand cuts'. But they also contribute to correcting insurmountable game design problems. For instance, one way of avoiding locks is to have a building reset meter, that allows the lock to be escaped through an unbeatable reset - essentially setting the game back to an earlier point of play. Similarly, Resident Evil 4 has a one shot rocket launcher that allows any single boss to be beaten. In the event a particular boss encounter cannot be overcome by the player, they can elect to use the rocket launcher to avoid the fight. Teleportation in Angband can fix issues in the random level design: where too many powerful monsters threaten the player in a single location, either they can escape or teleport the threats away from them. Liberal provision of resets can correct these kinds of hard-to-balance game design issues.

At the same time, resets should be a limited resource. If unlimited, there is no clear point at which a player should stop collecting them. Therefore, game progress can slow while the player tries to minimize the risk of failure by maximising the resources they currently have. Or equally the player can continue to attempt to save the resources for 'a rainier day' and never use them for the current encounter. This is a weakness particularly in RPGs with unlimited inventory. A design where it is obvious how to replenish lost resources will encourage the player to use what they currently have, and not dither around attempting to build up more.

4. Cloaking

Problem: It is hard to accurately represent stealth within a game, particularly a turn based game. Stealth and camouflage in nature relies on the presence of a visually noisier environment than can be currently modeled in game, and as a result, visual artefacts in character models and environmental models usually give away the presence of a hidden enemy much more readily than necessarily desired by the game designers.

Solution: Completely hide the enemy from the player, by removing the character model from the visual field when it qualifies as hidden. Then provide an alternate in game mechanic for detection, which may be as simple as removing the conditions which permit the cloak, having partially visible character models, such as a transparent version of the model, perhaps dripping with water, blood or other environmental effects if appropriate, or have one or more detector abilities which partially or completely reveal the character model when the ability is used.

5. Information

Problem: Information as a strategic resource has been greatly diminished in single player games, as well as many multiplayer player vs. environment games. Blame the rise of sites such as gamefaqs.com, as well as automated software capable of collecting details on the game space. However, the player may still require details about the environment around them if the map they are on is procedurally generated, or the enemies they encounter move in unpredictable fashion.

Solution: Information abilities are usually associated with providing details on the current location of enemies, or otherwise revealing information associated with the fog of war in games (either due to restrictions imposed by line of sight, or maximum perception distance). Information effects can be varied, provide partial or complete, or even inaccurate information to the player. Usually they are associated with the current state of play, but may attempt to make predictions about future events, or reveal past events.

As noted in the problem section, information abilities are less useful if they provide one-time information that remains static from game to game. This is the main difficulty in balancing information abilities: the diminishing returns through repeated play or by players resorting to external information sources (arguably cheating) may result in these abilities being underselected in the long run.

In addition, a trade off must always be made in the user interface to determine how much additional information to show the player, beyond what they are already aware of.

Information abilities may also be used to counter other abilities. This is typically true of the detection ability which counters an enemy's cloak ability. There must be a long term strategic disadvantage to using the information ability so that it remains interesting even once all parties have the information ability. In the cloak example, consider having some enemies have an ability that renders them invisible only when the detection ability is used. The cold suit in Dystopia is an example of this: Stealth is normally countered by switching to Infrared scanning, but infrared scanning renders players with the Cold suit invisible. Obviously, players cannot have both Stealth and Cold Suit simultaneously.

5. Door / key puzzles

Problem: Some abilities designs may not be as useful in normal game-play as intended, or their utility, function or the user interface required to activate them may not be intuitively obvious to the player. This can occur particularly if there are a large number of abilities available to the player. Typically, if the player has more than seven options total, they may have difficulty remembering all the available options at any time.

Solution: Block the player progress until they master a particular ability, by presenting a door puzzle that requires the player use the ability to open the door blocking their progress. The concept of a door is not necessarily literal: it could equally be a river, a lake, a boulder or other feature blocking the players progress, or equally a guardian or end of level boss of some kind, but it should clearly present an obstacle which is initially insurmontable but provides enough hints to suggest that the particular ability is required to overcome it.

This allows the game design to design game content moving forward from the door with the guarantee that the player has mastered this particular ability. For instance, newer content make take the place of skill or timing challenges using that ability or more complex puzzles with interrelated parts which have in-game appearance similar to the initial door challenge.

The risk with a door is that the player never understands or masters the ability, and gives up the game in frustration, or that the player button mashes their way around the problem without understanding the fundamental skills required.

6. Buffs and Build modifiers

Problem: A build and respec system may be used to balance magic abilities by arbitrarily reducing the powers of magic users, such as slower skill development, preventing them using edged weapons, heavy armour or forcing them to carry magic books, esoteric spell casting components or bind demons into their weapons. These disadvantages may be initially balanced, but later in the game cause player frustration as they overwhelm the pleasure of playing the game.

Solution: Provide temporary buffs which overcome some of the disadvantages designed into the initial build and spec system. Many spells can be seen in this light, such as the ubiquitous Shield spell that AD&D mages use. Equally, cure light wounds spells instead of potions, the ability to magically create food instead of carry it in a separate inventory slot, and magical means of generating light in Angband are effectively modifying the 'standard build' of an Angband character.

Buffs and Build modifiers make the build and respec system more complex and care needs to be taken that they do not end up too powerful. This can been seen in versions of Angband prior to 3.0 where mages could learn spells from one magic book that made them more effective fighters than the equivalent warrior - luckily this compensated for their weak attack spells (with the exception of Mana storm and Magic missile).

And it is balancing these attack spells so that they remain useful that is the focus of part six.

7 comments:

Mikolaj said...

> A reset sets the some or all

A good one. :D

Andrew Doull said...

Fixed.

Mikolaj said...

> This allows the game design to design game content moving forward

:D

Mikolaj said...

Otherwise, the easiest understandable installment in the Unangband Magic System series to me. Thanks. :)

Chronic said...

Just wanted to drop a note in and say thanks for writing these - I've been following along since the beginning and they've all been very well written and informative. I like the methodical approach you take to game design.

Keep up the good work, I'll go back to lurking now.

(and hi2u from New Zealand)

Alan Post said...

On the subject of cloaking, the table top game Star Fleet Battles handles cloaking in an interesting way.

A cloaked ship stays on the game board, but its effective range is much further away than its actual range, making the unit harder to hit.

In that game, cloak ships often have extremely powerful but slow to charge weapons. The strategy consists of being cloaked while charging the weapon, turning off the cloaking device to fire (you can't fire while cloaked), and turning it back on to recharge the weapon.

Snut said...

I'm really enjoying these, but this one kind of stuck with me:

5. Door / key puzzles

Because this is so often a point where the well-meaning game designer commits a horrendous sin of human interface design.

Basically, if you've got a locked door or some analog in your game with only one solution (in this example the mastering of a skill or skill set), you'd better be absolutely certain that your intended solution is the only remotely plausible one within the rules established in your world so far.

I know I hate it when I come up with an interesting solution to an in-game problem only to find that despite being perfectly reasonable, it's a no go. I didn't discover the correct way of doing it. Just seems something worth bearing in mind for a more general application of these very worthy guidelines :)