Earth, Wind, and Fire

Elemental damage is extremely common in RPG's, particularly turn based and Japanese RPG's. Rather than have damage be damage, many attacks do damage of a specific type, and many enemies (and often the player characters as well) take more or less damage from certain types of damage. Potentially, a well implemented system of elemental damage can add a dynamic strategic element to an RPG, but these systems are pretty much always poorly implemented.

Consider Final Fantasy X. The black mage of your party, Lulu, for the majority of the game, has only as many as 12 useful spells: a damage dealing spell in each of the four elements (fire, thunder, water, blizzard), each with three tiers of strength. Her other spells and basic attack are useless, and using items is rarely the right choice in combat, so whenever Lulu's turn comes up, the only questions you need to ask yourself are "How many magic points can I afford to spend?", "Which enemy is my highest priority to kill?", and "What spell will do the most damage?". The first two questions are sometimes a little tricky, but the last one never is. Spells of different elements within the same tier of power differ only in what type of damage they do. They cost the same amount of magic points and do the same base damage, so the best spell to use is always the one that does the most damage, which is rarely difficult to figure out. For example, if you're climbing an icy peak in the middle of the frigid Northlands, chances are pretty good that everything is weak against fire. Some bosses try to be tricky and change what element they're weak to, but they're never very sneaky about it. You generally don't even need to spend a turn to find out what the boss's new weakness is. All this does is make sure that the player isn't falling asleep. Towards the end of the game, you get access to spells that deal non-elemental damage, so they deal full damage regardless of the enemy's type. This should make things much simpler, but it really doesn't detract from the strategic elements of the game since choosing which spell to use is basically a non-choice to begin with. Part of the problem is that the spells differ only in the type of damage you do, and you almost always have equal access to spells of all four elements. If you didn't have equal access to different types of attacks, and there was a less arbitrary reason why different attacks did more or less damage to different enemies, you might have to make some more interesting choices.

Consider Paper Mario: The Thousand Year Door. Damage is damage. You don't have to check if your enemies are weak against fire or ice damage, crushing or piercing damage. Damage is damage. But that doesn't mean that all attacks are equally effective against all enemies. Whenever you attack an enemy, the damage you deal is reduced by their defense. Let's say you deal 8 damage, they have 2 defense, 8-2=6, so you deal 6 damage. However, if you have an attack that hits multiple times, your opponent's defense is applied for each hit. For example, if you have an attack that hits 2 times for 4 damage each, and your enemy still has 2 defense, you deal (4-2)+(4-2)=4 damage. So multi-hit attacks don't do so well against enemies with high defense. However, if you have a bonus to your attack, from an item or from your equipment, it's applied to all of your attacks. So, let's say you get +3 to your attacks, and your enemies still have 2 defense, your 2-hit attacks (assuming you still have 4 base damage) will deal (4+3-2)+(4+3-2)=10 damage. In paper Mario 2, you almost always have the choice between using 1-hit attacks or 2-hit attacks (or sometimes attacks with more hits), but depending on what gear you equip Mario with, you will be more capable of doing one over the other. The moral of the story here is that if you have more bonus damage than your opponent has defense, you are better off with multi-hit attacks. Otherwise, you should stick with 1-hit attacks. Therefore, in every area you adventure through, an important question you must ask yourself is "Am I capable of boosting my attack bonus higher than my enemies' defense, and what will I have to compromise to get my attack bonus that high?"

I'm not trying to say that any battle system using elemental damage is bad, just that there are a lot of wrong ways to do it. For an example of a game that handles elemental damage pretty well, consider Final Fantasy: Chaos Rings. In that game, there are only 3 elements, which, for clarity, I'm going to call rock, paper, and scissors. Square has a problem with giving unfamiliar names to intuitive concepts. Enemies come in all three flavors, and are weak or strong to other elements exactly how you'd expect them to be. A rock elemental attack will deal more damage to a scissors elemental monster, and less damage to a paper elemental monster. You do have the option to equip yourself with spells of each type at the same time, but the total number of skills and abilities you can have equipped at once is strictly limited, so in order to get that extra bit of versatility, you might need to compromise your character in other ways. What makes things really interesting though, is that after you cast an elemental spell in battle, your character gains an affinity for that element until the end of the battle, or until you cast another elemental spell. So if you cast a rock spell, that character's physical attacks will deal extra damage to scissors monsters, and reduced damage to paper monsters. That character will also take extra damage from paper monsters, and reduced damage from scissors monsters. If all of the monsters you're fighting against are of the same type, it's pretty easy to brace yourself with the right element, but battles are rarely so simple. It is more often the case that you will be fighting a rock monster and two scissors monsters. You could use paper magic to kill the rock monster quickly, but then the two scissors monsters will tear through your party. It would probably be better to use rock magic to kill the scissors monsters, leaving you on even footing with the rock monster. However, if the rock monster was 4 times more dangerous than the scissors monsters, then you might still be better off using paper magic to kill the rock monster before dealing with the scissors monsters.

Things get even more complicated during boss fights, since bosses generally have access to all 3 elements, which makes them very good at exploiting the player's weaknesses. Unfortunately, by midway through the game I had learned a few abilities which, when used together, enabled me to deal enormous amounts of non-elemental damage without gaining any elemental affinity, entirely sidestepping the game's elemental damage. Not only was this a much simpler way of beating bosses, but it was also much, much faster. I suppose I have only myself to blame for choosing to exploit such tactics, but I still think that Square should think a little harder about how they want people to play their games. But still. Points for trying.

Synergy

Synergy is when the end result of multiple efforts applied together is greater than the sum of those efforts individually. For example, if you have a few Valium or a few drinks, it'll help you relax, but if you take them together, you won't know what's what until you wake up dead. That's synergy.

To use a less grim example, cooking. Certain combinations of foods will taste better together than they will individually (i.e., B+L+T). Likewise, certain combinations of otherwise delicious food may taste wretched together (use your imagination). In part, this is what makes cooking interesting, that you can't just roll up all the best ingredients into a ball of 'win' and marinade it in awesome sauce, but you have to be mindful of how each ingredient interacts with the others. This also makes cooking a decent meal more complicated than equipping your party in nearly all RPG's.

Consider Final Fantasy IX. The game features an interesting system of passive abilities. Each character in your party can learn dozens of passive abilities, and can have several of them be in effect simultaneously at any given time. With that many choices, there is a staggering number of different combinations of abilities for even one character. Unfortunately, none of the abilities interact with each other synergistically, so choosing a set of passive abilities is often pretty simple; you're free to just choose your best abilities without worrying about how they interact with each other.

To be fair, there is one notable exception to this. "Auto potion" allows a character to use a potion (or high potion) out of turn after each time they are damaged, but even high potions heal too little health by midway through the game for this ability to be worthwhile. "Chemist" doubles the efficacy of certain items used by a character, but it still doesn't make those items good enough to warrant spending a turn to use them. Individually, these abilities aren't the greatest, but they complement each other such that they're viable when used together.

A game that uses a similar system much more effectively is Paper Mario: The Thousand Year Door. The player can equip Mario with both combat techniques and passive abilities, though in Thousand Year Door this done by equipping badges because Nintendo refuses to just call things what they are. Rather, they would have you believe that Mario simply wears his boyscout sash everywhere so he can constantly rearrange dozens of badges without poking too many holes in his overalls.

But the point is, many of these badges interact with each other in exciting ways. Finding one new badge in that games doesn't necessarily just give you access to one more effect, but may give you access to multiple new strategies, depending on what other badges you can combine it with. Some sets of badges may significantly change Mario's combat role, completely changing the basic battle tactics the player uses, or sometimes a group of 2 or 3 badges can make a badge combo where they have a powerful effect together that is qualitatively different from what they would do alone. In some cases, badges have subtle anti-synergy. A badge that helps you dodge attacks doesn't really play well with one that increases your defense, since every attack you dodge was an attack where your defense wasn't relevant.

The most notable badge synergy in Thousand Year Door is the 'Danger Mario' build. The game has many 'danger' badges, which have powerful effects that only trigger when Mario is almost dead. Individually, these badges are trash, since being 'almost dead' rarely lasts very long, as you'll generally either heal yourself or just die within the next turn. However, if Mario has all of the 'danger' badges equipped at the same time, then once you become almost dead, you become nearly unstoppable. The most important of the danger badges is 'Power Rush,' which increases your attack power by 2 (which is a huge boost in this game) when you're almost dead. The unfortunate thing is that with a little patience, you can buy as many Power Rush badges as you want, turning Mario into the Glassiest Cannon that ever there was and making the rest of the game comically easy. Like, kill-the-final-boss-in-one-turn easy.

So maybe Thousand Year Door takes synergy a little too far. But still. Points for trying.

Inventory

Inventory in RPG's is handled in many different ways. Some of the more traditional methods include 'infinite of anything,' as in most Final Fantasy games, where there is practically no limit on how much your party can hold. Similarly, some games, such as the Tales of Whatever games, use a 'little bit of everything' system, in which the party can hold any number of different items, but there is a limit to how many of the same item you can have. The last one I want to mention, and my personal favorite, is the system used in a handful of RPG's, such as the Mother games, in which you have a limit on the total number of items you can carry, and none of them stack. For example, lets say you're playing Mother 3, which has an inventory limit of 30 (I believe) for a party of one. Say you were traveling by yourself and harvested 30 pieces of dung, you would not have space in your inventory for even one loaf of bread, as may be the case.

In my opinion, the most important criterion on which one should judge an RPG is the rate at which the game forces the player to make difficult decisions. A game using an 'infinite of anything' inventory system doesn't really force the player to make any interesting decisions while she's standing behind the counter in the item store; the answer to the question "what do I buy here?" is almost always "more than enough of everything." Consumable items are usually inexpensive, and money is easy to come by in games where you can just grind for a few minutes outside of town till you have what you need (which is most RPG's). Games using a 'little bit of everything' model are little better. In this case, the answer to "what do I buy here?" is always "as much as the game will let me." Item shop decisions get much more interesting in games that impose harsh limits on your inventory.

Consider the game Evolution, an RPG for the Dreamcast. Your inventory space is severely limited, and to make things even trickier, money in the game is semi-finite. When you browse the item shop in Evolution, you have to ask yourself a lot of questions about the dungeon you're about to go into.

What status effects will I have to deal with here, and how frequently will I be inflicted with them? If one of my characters does get a negative status effect that I'm prepared to cure, is fighting with that status affect worse than spending a turn to cure it? Am I more concerned about healing light damage in multiple characters, or heavy damage in one character at a time? This depends on what monsters you are going to be fighting, as well as how you've chosen to set up your party. The answer to all of these questions will affect which items you buy, and in what proportions. Instead of being an errand you have to run before diving into the dungeon, the item shop is a meaningful part of the game.

But what about items that you don't buy in stores, those super rare consumable items that you save for a rainy day because they're just too awesome to use? Evolution has those too, but they don't usually invite you to make interesting decisions in the same way. One such item is the green moss, an item that you'd be lucky to find five of over the course of the game. Being that rare, most players would be compelled to save them for a potentially difficult battle in the unspecified future. It works out well enough in this case, since the only place where they're particularly necessary is against the final boss of the game. If you have around four or five of them, you can use a tactic that ends the fight in a few rounds when it would otherwise be a difficult battle. Until then, the player can just keep them in the storage locker in the protagonist's house, as not to waste precious inventory space on an item she probably won't be using any time soon. I imagine most players appreciate the storage locker, but as I see it, the storage locker robs the player of a chance to make an interesting decision.

Consider Super Mario RPG, Legend of the Seven Stars, the quirky offspring of Nintendo and Square. Many consider it a Beginner's RPG designed to initiate eleven year olds, but it has one of the most unforgiving inventory systems I've ever seen in a game. Your inventory can hold a grand total of 29 items, nothing stacks, and you have no storage. This makes things complicated right from the start. Ten minutes into the game, you are practically handed a Kerokerocola, a rare, powerful healing item which is also too awesome to use. It fully heals all members of your party, but at this point, your party consists of only Mario, so there obviously must be a better time to use it. Problem is, since there is no storage, as long as you are holding on to that cola, saving it for who knows what, you have effectively reduced your inventory to 28. It only gets worse from there, since this game is full of super unique items: a membership card to a top secret casino, a magical money bag that has infinite coins in it, etc. They all take up space in your already tiny inventory. For each of these rare or unique items in your inventory, you have to choose between long term security, knowing that you have a very useful item in case the situation should demand it, and the immediate benefit of extra inventory space that you get from discarding the item, never to be seen again.

Unfortunately, the game just generally isn't difficult enough that you'd ever need the extra inventory space. But still. Points for trying.