What does Hand Infantry Combat do in AoE3?

Doppelsoldner: hit points +15%, damage +15%; Pikeman: hit points +15%, damage +15%; Ships 3 Uhlan. The game says: "Doppelsoldner and Pikeman attack and hitpoints increased, +3 Uhlans."

Home City card

Hand Infantry Combat

Hand Infantry Combat (tech ID HCHandInfantryCombatGerman) is a Home City card in AoE3: Definitive Edition 100.19.18309, in the decks of 1 civilization, sent from the Fortress Age. Effect: Doppelsoldner: hit points +15%, damage +15%; Pikeman: hit points +15%, damage +15%; Ships 3 Uhlan. It hands over about 450 resources' worth.

Quick answers (3)

Which civilizations have the Hand Infantry Combat card?: Germans.
What does Hand Infantry Combat do in AoE3?: Doppelsoldner: hit points +15%, damage +15%; Pikeman: hit points +15%, damage +15%; Ships 3 Uhlan. The game says: "Doppelsoldner and Pikeman attack and hitpoints increased, +3 Uhlans."
What is the tech ID of Hand Infantry Combat?: HCHandInfantryCombatGerman.

Doppelsoldner and Pikeman attack and hitpoints increased, +3 Uhlans.

What it does

Doppelsoldner: hit points +15%, damage +15%
Pikeman: hit points +15%, damage +15%
Ships 3 Uhlan(unit)

What it hands over

3 × Uhlan150 each

Total ≈ 450 resources — units at their train cost, crates and animals at what they hold.

Cost: 1
Sent from: III
Times it can be sent: 1
Game ID: HCHandInfantryCombatGerman

In these decks

GermansIII×1

Source: techtreey.xml and the Home City files, AoE3: DE 100.19.18309 (build 25040513).