In MMOs, there are typically several different "dice rolls" to determine the type of hit you make (or not) and the way that your baseline weapon damage is scaled up or down depending on the type of hit you make.

Note: no developer has specifically stated the hit roll order and prioritization, but we can guess at it based on the types of hits we observe over time. My breakdown differs from another common breakdown you see on the forums, but the end result is the same. I'm just very exacting about these things. It is very difficult to empirically test these types of mechanics, but my breakdown takes into account the existence of several offensive and defensive stats whos existence is not explained by the "other" common breakdown.

There are five rolls in the following order for every hit. Even for each individual "tick" of a multi-hit attack (Burst, Frenzy, Focus, and Chain)

Evaded? (If yes, stop here) Glancing? (If yes, skip the Crit roll) Critical? Blocked? (If yes, skip the Penetration roll) Penetrated?

That's it: 5 successive rolls. Glancing and Crits are mutually exclusive and will never happen in the same hit. The Glance check takes precedence over the Crit check. Likewise for Blocked/Penetrated, with the Block check taking precedece over the Penetration check.

Damage scaling (of the base damage value of the ability) in order of highest to lowest is as follows. Note that the scaling is very likely different in PvE versus PvP, and in PvE it's likely different when a player hits a mob versus when a mob hits a player. And in each of these three cases, the scaling will vary further based on how much or how little the stats being checked for differ between the attacker and defender. So trying to specify exact scaling values is fruitless. Empirical observation plus a few dev statements here and there suggest the following relative order.

Critical (positive-scaled damage) AND Penetrated (reduced by negative-scaled Protection)

roughly equal damage: Critical (positive-scaled damage and reduced by non-scaled Protection) Penetrated (non-scaled damage and reduced by negative-scaled Protection)

Critical (positive-scaled damage) AND Blocked (reduced by positive-scaled Protection)

Normal (non-scaled damage and reduced by non-scaled Protection)

Blocked (non-scaled damage and reduced by positive-scaled Protection)

Glancing (negative-scaled damage) AND Penetrated (reduced by negative-scaled Protection)

Glancing (negative-scaled damage and reduced by non-scaled Protection)

Glancing (negative-scaled damage) AND Blocked (reduced by positive-scaled Protection)

Evaded (0 damage)

There are two important things to understand about the effect of your Magical Protection and Physical Protection stats per the preceding list:

Protection in TSW is the equivalent of percentile-reduction "armor" in other MMOs: Some MMOs use absorption armor that takes a flat amount of damage off the top of every hit. Some MMOs use percentile-reduction armor that simply reduces the damage of a hit by a certain percent. TSW's Physical and Magical Protection works like this.

Penetrating hits do not ignore all Protection. The exact amount ignored is unknown, but a dev has stated that (paraphrasing) "In most cases, over time, the extra damage from Crits should be roughly equal to the extra damage from Pens". This is why the 2nd and 3rd bullets in the list above (normal Crits and normal Pens) are listed as being roughly equal damage.

What stats are being checked in each roll?

Evade roll:

The defender's Evade Chance is compared to the attacker's Enemy Evade Chance. The attacker's percentage is subtracted from the defender's percentage before making the roll.

You start out with a 5% base Evade Chance at 0 Evade Rating, and this percentage increases further as you add more Evade Rating through gear or ability buffs. For example: 153 Evade Rating = 7.3% Evade Chance 261 Evade Rating = 8.9% Evade Chance

You start out with a 0% base Enemy Evade Chance at 0 Hit Rating, and this percentage increases further as you add more Hit Rating through gear or ability buffs. For example: 250 Hit Rating = 0.9% Enemy Evade Chance 492 Hit Rating = 1.8% Enemy Evade Chance

The amount of negative damage scaling for an evaded hit is fixed at 0% of their normal baseline value (100% damage reduction).

Glance roll:

The defender's (hidden) Glance Chance is compared to the attacker's (hidden) Enemy Glance Chance. The attacker's percentage is subtracted from the defender's percentage before making the roll.

You start out with a 10% base Glance Chance at 0 Defense Rating, and this percentage increases further as you add more Defense Rating through gear or ability buffs.

You start out with a 0% base Enemy Glance Chance at 0 Hit Rating, and this percentage increases further as you add more Hit Rating through gear or ability buffs.

The amount of negative damage scaling for a glancing hit is fixed, and the only scaling value we know for certain is that when a player hits a PvE monster, such glances hit for 40% of their normal baseline value (60% damage reduction).

Note: Neither of these two percentages are actually visible in your character sheet. The 10% value for Glance Chance comes from a developer statement very late in closed beta. The 0% value for Enemy Glance Chance was visible in Closed Beta for a while.

Crit roll:

The attacker's Critical Chance is compared to the defender's Enemy Crit Chance. The defender's percentage is subtracted from the attacker's percentage before making the roll.

You start out with a 5% base Crit Chance at 0 Crit Rating, and this percentage increases further as you add more Crit Rating through gear or ability buffs.

You start out with a 0% base Enemy Crit Chance at 0 Defense Rating, and this percentage increases further as you add more Defense Rating through gear or ability buffs. For example: 150 Def = 0.5% Enemy Crit Chance

The amount of positive damage scaling for a critical hit starts at a base value of 125% for 0 Crit Power, and this percentage increases further as you add more Crit Power through gear or ability buffs.

Block roll:

The defender's (hidden) Block Chance is compared to the attacker's (hidden) Enemy Block Chance. The attacker's percentage is subtracted from the defender's percentage before making the roll.

While neither tested nor stated by a dev, my personal guess is that this roll works identically to the way that Evade and Glance rolls work, and that there is an underlying Block Chance and Enemy Block Chance that is used for the roll as follows:

You start out with a 10% base Block Chance at 0 Block Rating, and this percentage increases further as you add more Block Rating through gear or ability buffs.

You start out with a 0% base Enemy Block Chance at 0 Penetration Rating, and this percentage increases further as you add more Penetration Rating through gear or ability buffs.

The amount of negative damage scaling for a blocked hit is variable (because it scales up the defender's Protection value). From testing, it appears that in PvE situations, on average, when a player hits a PvE monster, such blocks hit for 60% of their normal baseline value (40% damage reduction).

Note: Neither of these two percentages are actually visible in your character sheet. Both values are extrapolated as my personal "guesstimate" from the way that Glance rolls work.

Penetration roll:

The attacker's (hidden) Penetration Chance is compared to the defender's (hidden) Enemy Penetration Chance. The defender's percentage is subtracted from the attacker's percentage before making the roll.

While neither tested nor stated by a dev, my personal guess is that this roll works identically to the way that Crit Chance rolls work, and that there is an underlying Penetration Chance and Enemy Penetration Chance that is used for the roll as follows:

You start out with a 5% base Penetration Chance at 0 Penetration Rating, and this percentage increases further as you add more Penetration Rating through gear or ability buffs.

You start out with a 0% base Enemy Penetration Chance at 0 Block Rating, and this percentage increases further as you add more Block Rating through gear or ability buffs.

The amount of negative damage scaling for a penetrating hit is variable (because it scales down the defender's Protection value), and the only thing we know for certain is a developer/designer statement that "over time, the damage output for crits and pens (in PvE) will be roughly equal"

Note: Neither of these two percentages are actually visible in your character sheet. Both values are extrapolated as my personal "guesstimate" from the way that Crit rolls work.