The Tower of Time has some conventions that are a bit different than most RPGs. Best to know them before you find out the hard way!
So sit right back and let me set you straight.

Might adds to weapon damage, speed makes your attacks go faster, mastery adds to the effect of skills, and life gives the character more hit points. Simple enough. What’s different is that this is true for all character classes. If you want your archer to do more damage with arrows, add to her might. If you want your druid’s wand to hit harder, add to his might!

Armor protects against physical damage on a point for point basis. If you have 30 armor and get hit for 50 damage then you just take 20 points of damage. If an enemy has a lot of armor and you hit it with a bunch of small attacks, you aren't going to do much damage. You're better off using big weapons that can punch through the armor and still do damage.

Many weapons and some other items have an armor penetration stat. That just means the weapon automatically penetrates that number of armor points. Unless your enemy has very little armor (i.e. there's no armor to penetrate), it's the same as adding damage to your physical attack.

While armor works on points, elemental powers work on percentages. If you hit an enemy with a 50 point fire attack and that enemy has 50% resistance then you’ll only do 25 points of damage. If it has a -50%, though, you’ll do 75 damage!

Elemental penetration subtracts a percentage from the enemy's resistance. If you hit the enemy with a 50 point fire attack, that enemy has 50% resistance to fire, but you've got 10% penetration then you'll do 60% of 50 points of damage, so 30 points.

So, does everybody remember that whole distributive[en.wikipedia.org] thing from their math classes? Time to put it to use! If the enemy has 50% resistance to your attack and you hit it with 5 attacks doing 20pts each, you will do 10+10+10+10+10 damage for a total of 50pts. If you hit it with one attack doing 100pts it will still do 50pts. If these had been pysical attacks against 50 armor, the five attacks would do 0+0+0+0+0 damage for a total of dink while the 100pt attack would do 100 - 50 = 50pts of damage. Breaking up elemental attacks into multiple attacks doesn't really matter but it sure does with armor.

Gold: Used for raising levels. It’s also used for upgrading the buildings. You can not use gold to buy items or sell items for cash! Essentially, gold acts like experience points in other games.

Crystals: These are the currency of items. When you get the blacksmith going and upgraded you can use crystals to create new, random items, or enhance your existing items. You can also combine 3 green crystals into one blue or 3 blues into one purple once the transmute option opens up. You can also destroy items you no longer want for crystals.

Loot: Magic weapons and armor. Between battles and chests, you’ll get plenty of these! Your inventory appears to be pretty huge but don’t hang on to items you’re pretty sure you won’t use. Magic (green) items are typically the weakest, ancient (blue) items are a bit stronger, then relic (purple) items, and finally legendary (yellow) items. Items also have a level, which you can see as roman numerals in the lower right corner of the item’s icon in your inventory. Don’t be lazy, though! That purple helmet might have more power than the green one you’re wearing but your green may be adding something you really need while the purple has strengths that don’t help you.

Purple “relic” items can be enchanted with the enchantments you find lying around in the tower or earned in challenges. Once you learn an enchantment, you can use it as many times as you like. Each costs a number of purple crystals, making those crystals very valuable. If you don’t like an enchantment, you can put a different enchantment on the relic but I don’t think you get any credit for the original – it’s simply wasted. Yellow, legendary items with enchantments can’t be re-enchanted with something different.

You can also use crystals to make completely new items. I haven’t used it much but it will make a new, random item for you. You get to pick the type of item, the level, and whether it’s magic, ancient, or relic. The rest is a roll of the dice.

The item forge is another way to enhance your stuff. If you look at the details of your item, there should be at least one square in the upper left. Those are slots for the item forge to work with. Once the item forge opens up, you can use it to enhance the item as many times as there are slots. The first enhancement just costs green crystals, the next blue, and after that it costs purples. The more powerful an item is, the fewer slots it will typically have.

Forges also exist within the tower. These can increase the power of one of your items. If you improve a blue (ancient) item, it will turn into a relic and you’ll be able to enchant it. The item retains all of its item forge slots, too, and may even gain one.

There are lots of special rewards, too. Magic scrolls in the tower will let you permanently add to your characters’ statistics, though the biggest ones will typically take something away as well. Fountains will permanently add or subtract statistics as well. Be sure to inspect the fountain – if it looks nasty then it probably will subtract!

After you get through the prologue and get your first two characters, you’ll have just three skills. As you play the game and collect more gold, you’ll buy new levels in the barracks. Doing so gives you more attribute points, more skill points, and access to more skills.

Attribute points are pretty straightforward. It is pretty easy to forget to click the “apply” button but, if you do forget, you’ll see a number in the lower left of your character’s portrait so you can pop right back in and do it right. If you decide you don’t like how you distributed your skill points, you can spend some crystals to reset them.

Skills are more interesting. Each skill has a main line through the center and two lines of skills along the side. For instance, the side lines of Maeve’s fire arrows let you pick decide to either make them do more criticals or have them explode (and no, you can’t have both). You can only have four skills at a time so, when you get your fifth skill, you’ll be able to pick which skill you want to swap out in the lower left part of the screen.

Unlike attributes, you can swap out skills any time you’re not in the battle screen. It doesn’t cost a thing! If you’ve been using the Maeve’s explosive arrows against swarms of enemies and you come up against a lone boss, you can switch them out for the ones that can do more criticals, then switch them back to explosive again after the battle is won. Many encounters let you look over enemy stats and skills then use the “withdraw” option to back off of the battle – which gives you a perfect chance to change your skills around to meet the new challenge. (Most levels stick to just a few enemy types so you shouldn’t have to switch your skills around every fight.)

You can return to any level in the tower. You don’t need to complete everything on a level before going down the stairs. Some enemies are pretty difficult and will require that you come back later.

All characters can wield two weapons. Doing so lets you take advantage of the bonuses on both weapons, though the left hand’s weapon will do half damage.

Only fighters can use shields and only on the left hand. Mages with shields, while Original, would be a Sin against RPG standards! ;)