Comparison of Armorer, Offense and Archery

Facts (valid for Horn of the Abyss)

• At Basic, Advanced or Expert Level, Armorer reduces all damage inflicted by 5%, 10% or 15%.
• At Basic, Advanced or Expert Level, Offense increases hand-to-hand damage by 10%, 20% or 30%.
• At Basic, Advanced or Expert Level, Archery increases ranged damage by 10%, 25% or 50%.
• 9 heroes (+ 1 campaign hero Roland) start with Armorer as a secondary skill and 3 specialize in it Mephala, Neela and Tazar.
• 23 heroes (+ 4 campaign heroes Kilgor, Catherine, Bidley and Tark) start with Offense as a secondary skill and 3 specialize in it Crag Hack, Gundula and Corkes.
• 9 heroes (+ 1 campaign hero Gelu) start with Archery as a secondary skill and 1 specialize in it Orrin.

Notes

• Armorer will benefit all your troops while Offense will benefit shooters less (only when they attack in melee).
• Archery has the biggest bonus, but only works for shooters.
• Inferno, Necropolis and Fortress have 1 shooter, Tower has 3 and all other towns have 2 shooters. Probably, because Archery applies to fewer stacks in your army, the bonus is bigger to balance the skill.
• Beastmasters from Fortress are most likely to learn Armorer (10% chance), followed by Alchemists from Tower (8% chance).
• Barbarians from Stronghold are most likely to learn Offense (10% chance), followed by Captains from Cove (9% chance).
• Captains from Cove are most likely to learn Archery (9% chance), followed by Rangers from Rampart and Planeswalkers from Conflux (8% chance each).

Table of specialties percentages

Assuming Expert Level in the secondary skill, the bonus will increase to the following values at certain levels: (Level 74 is the maximal level in Horn of the Abyss).

Bonus Percentages from Specialty
	Armorer	Offense	Archery
Base %	15%	30%	50%
Level
0	15%	30%	50%
1	16%	32%	53%
2	17%	33%	55%
3	17%	35%	58%
4	18%	36%	60%
5	19%	38%	63%
10	23%	45%	75%
15	26%	53%	88%
20	30%	60%	100%
25	34%	68%	113%
30	38%	75%	125%
40	45%	90%	150%
46	50%	99%	165%
47	50%	101%	168%
50	53%	105%	175%
60	60%	120%	200%
70	68%	135%	225%
73	70%	140%	233%
74	71%	141%	235%

Discussion

Note that all three skills' percentages increase linearly when their respective specialty heroes reach higher levels.

Now, for Offense and Archery the resulting advantage also increases linearly: Offense specialty adds a 100% (linear) bonus every 66 2/3 levels after level 46 2/3. Archery specialty adds a 100% (linear) bonus every 40 levels after level 20.

Armorer behaves non-linear. This is because the change from 15% reduced damage to 20% reduced damage is less of a difference than 90% reduced damage to 95% reduced damage. From 15% to 20% the change is only a 5.9% improvement, but 90% to 95% halves the damage taken!

Tabular Overview #1

Here a tabular overview of what levels would be needed to double/triple/... the damage or to receive only half/one third/... of the damage:

	Armorer			Offense			Archery
Base %	15			30			50
	Level	Total %	Effective Reduction Factor	Level	Total %	Effective Increase Factor	Level	Total %	Effective Increase Factor
Two times / One half of damage	46.67	50%	2	46.67	100%	2	20	100%	2
Three times / One third of damage	68.89	67%	3	113.33	200%	3	60	200%	3
Four times / One fourth of damage	80	75%	4	180	300%	4	100	300%	4
Five times / one fifth of damage	86.67	80%	5	246.67	400%	5	140	400%	5
Ten times / one tenth of damage	100	90%	10	580	900%	10	340	900%	10
At max level	74	71%	3.39	74	141%	2.41	74	235%	3.35

Tabular Overview #2

Here the table for achievable levels:

Effective Increase / Reduction Factor
	Armorer	Offense	Archery
Base %	15%	30%	50%
Level
0	1.18	1.30	1.50
1	1.19	1.32	1.53
2	1.20	1.33	1.55
3	1.21	1.35	1.58
4	1.22	1.36	1.60
5	1.23	1.38	1.63
10	1.29	1.45	1.75
15	1.36	1.53	1.88
20	1.43	1.60	2
25	1.51	1.68	2.13
30	1.60	1.75	2.25
40	1.82	1.90	2.50
46	1.98	1.99	2.65
47	2.01	2.01	2.68
50	2.11	2.05	2.75
60	2.50	2.20	3
70	3.08	2.35	3.25
73	3.31	2.40	3.33
74	3.39	2.41	3.35

Tabular Overview #2

Here the table for achievable levels:

Effective Increase / Reduction Factor
	Armorer	Offense	Archery
Base %	15%	30%	50%
Level
0	1.18	1.30	1.50
1	1.19	1.32	1.53
2	1.20	1.33	1.55
3	1.21	1.35	1.58
4	1.22	1.36	1.60
5	1.23	1.38	1.63
10	1.29	1.45	1.75
15	1.36	1.53	1.88
20	1.43	1.60	2
25	1.51	1.68	2.13
30	1.60	1.75	2.25
40	1.82	1.90	2.50
46	1.98	1.99	2.65
47	2.01	2.01	2.68
50	2.11	2.05	2.75
60	2.50	2.20	3
70	3.08	2.35	3.25
73	3.31	2.40	3.33
74	3.39	2.41	3.35

This leads to the following conclusions:

• Without a specialty in Armorer, Offense or Archery, Armorer is statistically worse in a fight where you take similar amounts of damage as you inflict. 15% damage reduction cannot compete with 30% or even 50% damage increase.
• Because Armorer gets super-linearly better at higher levels for Armorer specialty heroes, it can break even with Offense at level 46 2/3 and with Archery at level 73 1/3. This means at these levels, the skills are equal: If the base damage is 100 (with Offense specialty and Expert Offense) at level 46 2/3 the creature does 100% more damage. The defending creature (with Armorer specialty and Expert Armorer) will reduce the taken damage by 50%, so will only receive the 100 damage. This cancels each other out exactly. Before the mentioned levels, Offense and Archery will effectively increase the original damage while at later levels, the taken damage will be less than the original damage.
• This does not mean that Armorer is worse than Offense or Archery until the mentioned levels. To preserve army hit points is a very important goal and Armorer does exactly this.
• Offense and Archery are only preserving hit points in a passive way: You need to kill enemy stacks before they can hit you.
• Against shooters which can't be reached in the first round, Armorer will probably be more useful.
• Against fast creatures which get the first strike, Armorer might be more useful. More of your creatures survive the initial attack. They might even do more damage than if you had Offense or Archery since there are more left.
• These are all great skills. While Archery is more situational (probably especially useful for Towers Titans), Armorer is universally useful and Offense will significantly benefit basically any army as well. For might heroes these skills are very important while magic heroes might now have enough secondary skill slots to learn them. Also, their chance to learn these skills is generally lower.