By Hammer
If you came here for Illiani and a deep dive into MekHQ economics, so did I. Illiani’s post went out on time, by HPG, and ComStar has it sitting in the queue behind a Precentor’s birthday greetings. Until the transmission fee clears, you’re stuck with me and the infantry. Infantry are cheaper than economists anyway. Ask any merc commander.
The red light came on in Karnov Three, and Sergeant Pike stood up in the middle of the troop bay like he'd been waiting all week for it.
"All right, listen up. Briefing's short because the ride's short." He slapped the bulkhead. "Hollis and his jump troops drop on the flak guns. We land on the vehicle pad and take the fab hall."
What’s New
Infantry have a reputation at the tabletop. There are a lot of rules, they’re spread across Total Warfare, Tactical Operations, the TechManual, and years of errata, and many of them are abstract enough that tracking them by hand slows the whole game down. MegaMek does that bookkeeping for you, which is a big part of why infantry are one of the most popular units in MegaMek. Players are always asking for more from them.
That same complexity makes infantry one of the hardest things in BattleTech to get right in code, and we’ve been getting a steady stream of questions and bug reports to prove it. So for 0.51.01 we went back through infantry to fix as many of those issues, and finish as many of the half-implemented rules, as we reasonably could. That covers everything from how they fight inside buildings to what they carry, how they get off a VTOL, and what they breathe. Here’s what’s new, and why it makes your platoons more interesting to play.
Infantry Actions in Buildings
"Kurita's got flak emplacements ringing that pad, with a platoon dug into each one," Pike said. "Hollis lands on top of them and clears them out room by room. The gun crews fight too, so don't expect them to sit it out."
Infantry vs. infantry fighting inside buildings has been in MegaMek for a couple of releases, but the old version was rough around the edges. We’ve reworked how it’s presented and gone back to Tactical Operations: Advanced Rules (pp. 169-174) to make sure the implementation is full and accurate.
The attacker declares an action against a building, and the defender answers with the infantry inside and part of the building’s crew. Yes, that means the gun crews get a say. Each building gets one roll in the End Phase, and the report now tells each round as a short narrative with linked unit names, then lists casualties for each unit, so you can actually follow what happened.
Step 1. Your platoon is inside an enemy gun emplacement, and MegaMek asks whether you want to start something.
Step 2. Pick who goes in. This platoon brings 33.75 Marine Points, counted as 34.
Step 3. The defender gets asked. Commit nothing, and the building falls.
Step 4. The defender commits its only crewman. Half a Marine Point against 34.
The old version also got the casualties backwards. Each side lost a share of its own strength instead of its enemy’s, so a big platoon attacking a lone crewman could bleed out on its own. Losses now come from the other side’s strength, and strength comes from the Marine Points tables as printed, so heads aren’t everything. An Elemental is worth more than two riflemen, and battle armor earns its points from its suits and weapons.
Two fights in two emplacements, both still going. The story first, then the odds, the roll, and who lost how many.
Once infantry commit to an action, they hold their ground. They don’t move, target, or make attacks elsewhere. The only way out is to withdraw, and withdrawing costs you one last exchange at half damage. The book doesn’t say whether engaged infantry can move, so this is our call. It sits behind an option, Infantry actions: committed units hold their ground, under Advanced Combat > Infantry Actions. It’s on by default, so you can turn it off if your table reads it differently. There’s also a house-rule option that lets defenders withdraw.
Attacking: reinforce, carry on, or tick the box and pull out at half damage.
Defending: commit crew, or, with the house rule on, withdraw and give up the building.
Units wiped out in an infantry action used to show up as “pilot error” in the end-of-game summary. The kill now goes to the other side, where it belongs.
The bots fight these too. Princess and CASPAR now declare infantry actions the way a player does. They’ll start one when the odds look good, reinforce one they’re winning, defend their own buildings with the infantry inside and part of the crew, and withdraw when it turns against them. How eager they are depends on their behavior settings. Like everything else Princess does, she won’t always make the call you would.
Some limits for now. A captured building currently just sits there. Two attackers who are hostile to each other in the same building aren’t modelled. Manei Domini score like regular troopers, because the unit data can’t tell them apart yet.
Taking the Guns
Kurita’s flak emplacements are Advanced Buildings, and they got plenty of attention this release too. An infantry action is only as good as the building it’s fought over.
Emplacements now come with a crew. A building’s unit file can list one, and if it doesn’t, MegaMek works it out from the minimum crew table: gunners for the heavy weapons, people for the communications and support gear, and officers to run it. That’s the crew that answers when Hollis comes through the door, and an infantry action can now thin it out a few at a time instead of only wiping it out in one go.
The guns play fairer too. An emplacement used to be able to fire on infantry inside its own hexes, so a platoon that had already fought its way in could be shot by the turret over its head. That’s gone. Turrets now take weapon damage and critical hits properly, and a crew with a jammed gun can clear it. And when MegaMek places emplacements on a map for you, it no longer uses the logic meant for units that move, so they stop turning up in odd spots around town.
When the Building Becomes the Target
"And the fab hall?" Lindqvist asked. "What are we walking into?"
"Medium construction. Walls eat most of what a 'Mek throws at you."
"How much is most?" Private Teague asked.
"Depends on the gun. And before you ask, there's a basement. Small. Nothing bigger than a man fits down there."
"So, me."
"So, you, Teague."
Until now, MegaMek gave Teague the wrong answer. Every weapon turned into casualties the same way, so a large pulse laser and an AC/20 into a medium building both killed one trooper, and a second platoon in the same building got short-changed. Now each weapon counts by its own damage, and every platoon inside takes the full share. That large pulse laser kills three troopers. The AC/20, for all its noise, still kills one.
A PPC into an occupied medium building. Five points carry through, and the platoon inside loses one trooper.
That wasn’t the only thing wrong with buildings. The walls were cutting down fire from enemy infantry, and they shouldn’t. Gun emplacements took the infantry’s share before halving the attack, instead of after. Platoons right next to the building rolled to see how many troopers hit, when every one of them should. And a shot that only hit the building because it was in the way still hurt the people inside. Now only a deliberate attack on the building gets through to them.
Infernos had the same problem. Any inferno that hit a building hex burned the infantry inside at full strength, even through a hardened building. Now they burn at the building’s share, and only on the level they struck. A hardened building keeps them out entirely.
The building also stops handing out cover it shouldn’t. Only a ‘Mek gets partial cover from a building now. Large support vehicles, DropShips and ProtoMeks used to get it just for being tall enough. That big Kurita cargo hauler parked behind the fab hall is a target now, not a wall.
As for Teague’s basement, a roll of 9 on the Basements Table now gives you a small basement that only infantry can enter. Before this, MegaMek treated anything below ground as water, which made for some very confused infantry.
A small basement, and a platoon already down in it at elevation -1.
Fighting Floor to Floor
Once Teague’s platoon is inside the fab hall, the building stops being cover and becomes the battlefield. A couple of things were off in there.
When a unit inside a building fired at infantry on another floor, MegaMek used the numbers for attacks from outside. A heavy building soaked up half the damage instead of a quarter, and a hardened building three quarters instead of half. Fights between floors now hit as hard as they should.
Shooting up at a higher floor of your own building never used the Below hit table, either. Now it does, and a building’s own weapons fire from the level they’re mounted on.
Getting the Weapons Right
Hollis came over the net. "Captain Kade, Hollis. One's loaded. Jump platoon, SRMs are Infernos, declared at the depot."
Teague leaned toward Pike. "Infernos. Those the same as our grenades?"
"No. The grenades are Incendiary now. They burn people. You throw one at a tank, the tank laughs at you."
"Says who?"
"Says the errata, Teague. Read a book."
The pilot cut across the net. "Kurita's got LRM carriers in the valley. If they throw Swarms, they'll go for the big stuff first."
"And if they miss?" Teague asked.
"Then they go looking for the nearest platoon," Pike said, "and that platoon eats every last missile. So don't be the nearest platoon."
Incendiary, not Inferno. Following the TechManual errata, 17 infantry flame weapons have been renamed from “Inferno” to “Incendiary.” They were never Inferno munitions, and the old name had players expecting them to cook vehicle crews. Against vehicles they do damage, not heat, and the log tells you why. Old unit files and saves still load under the old names.
Infernos are a choice you make before the drop. Any SRM platoon now picks Inferno or Standard under Configure > Equipment > Carried Munitions, and that’s what it has for the whole battle. Inferno fires half the platoon’s Damage Value in missiles. The separate Inferno SRM launchers are gone, since the errata deletes them, so the Elephant beast infantry now mounts the plain two-shot launcher and gets a bump in damage and BV.
Hollis's jump platoon, set to Inferno before the drop. That's what it fights with all battle.
Heavy Burst. Both halves of Heavy Burst were wrong. Whether your platoon got its extra die depended on what the platoon you shot at was carrying, and seven weapons never got their point blank bonus. Both are fixed, and the damage report now tags it, so you can see what it added.
Heavy Burst, tagged on the line: +6 on the first volley, +3 on the second. And that caustic air adds a point of its own.
Swarm missiles. The Karnov pilot’s warning is the rule now. A Swarm volley that hits conventional infantry stops there, because the platoon absorbs every missile. When leftover missiles look for a new target, every unit in an adjacent hex is now a candidate, not just one per hex.
Flame damage. Battle armor with pain shunts now halves flame damage like conventional infantry. Heavy and vehicle flamers get the proper halving against mechanized infantry and inside buildings. Fire-Resistant battle armor now ignores the heavy flamer too.
The data. We corrected 67 infantry weapons against the TechManual tables, registered two that were missing, and added 15 light machine guns from Shrapnel. Needlers, stunners, and dart guns also stop reporting damage they can’t actually do to armor. Fair warning: the BV of some infantry forces will shift.
Getting On and Off
"Cap'n, Mbeki. If that pad's hot, my people can make the drop."
"You can make a thirty-meter fall, Sergeant. Once. Hollis has jump packs. You have feet. You go when they land."
"Voss, how's the ride?"
Voss and his battle armor squad were clamped to the hull of Lieutenant Hunter's BattleMaster. "Bumpy. No jump jets on these suits, so if anybody grabs onto a VTOL and it climbs, we're coming off it the hard way."
Under the errata, foot troops now stay aboard a VTOL or WiGE until it sets down. Only infantry with jump or VTOL movement can leave one that hasn’t landed. Jump troops over a building land on the roof and count as having jumped.
Battle armor shaken off a VTOL used to take the same single 3D6 hit as a rifle platoon, however high it was flying, and none at all if the VTOL was shot down under them. Now every trooper takes a point for each level they fall, so Voss is right to worry. Jump-capable suits still land safely, but they can’t move or shoot that turn.
VTOL beast infantry can now fly over deep water, and an airborne beast platoon spends movement just to hold its position.
Bad Air and Personal Gear
"Valley air's caustic," Pike said. "XCT seals stay on the whole time. Anybody pops a mask down there gets to find out what their lungs taste like."
"Sarge," Teague said, "I dig holes for a living. My lungs already taste like dirt."
"Then you'll hardly notice the difference."
"Hunter," Kade said over the net, "if you punch out down there, keep that sidearm holstered. Kurita doesn't shoot pilots who don't shoot first."
"Noted," Hunter said, sounding bored.
Tainted and toxic atmospheres are new in 0.51.01. Infantry now need XCT training and the right gear to take the field at all in that air. The caustic point in the Heavy Burst report earlier was this air at work.
Pick the air in Planetary Conditions. Caustic (Tainted) for Pike's valley.
In the game, Ctrl+P shows it on the map.
Crews can now wear personal armor kits that keep protecting them after they eject, whether that’s a space suit, a snowsuit, an environment suit, or a MekWarrior combat suit for toxic air and heat. Ejected and dismounted crews also keep their own sidearm instead of picking up a generic rifle. Kade’s advice still stands: Princess only respects pilots who don’t shoot at her.
Hunter's kit for the drop: a MekWarrior Kit, a laser pistol, and a Small Arms skill to use it with.
In Your Campaign
If you play MekHQ, a lot of this follows you into your campaign.
Issue Kits in MekHQ. Kits come out of stores, a shortfall is ordered, and the tags say which ones handle hot, tainted or toxic air.
- Disposable infantry weapons are tracked trooper by trooper. You can buy them in bulk, with one successful roll filling a whole platoon’s order, and reloads draw from the warehouse first.
- Armor kits are real parts, priced by MegaMek. Swapping them is a refit, and infantry can quick-swap theirs.
- Refits that rearm a platoon now buy proper infantry weapons instead of leaving generic ones behind.
- A new campaign option lets your techs and mechanics look after conventional infantry instead of the infantry doing it themselves.
- Dismounted crews fight using their best infantry weapon skill.
- Survival gear: infantry were deploying without it. That’s fixed.
- Battle armor suits now belong to the trooper wearing them. When a suit is lost, the trooper inside is the casualty, not some random member of the squad. Refits keep each trooper’s suit, and destroyed suits can be replaced again.
Wrapping Up
"Two minutes," the pilot called.
The Karnov bucked as something on the ground found its range. Pike grabbed a strap and didn't even look up.
"All right, people. Let's go take a building."
Some games you’ve played before will come out differently now, and that’s intended. I’ll be straight with you, though: the infantry rules are huge, and I have no doubt we’ve still missed things. There will be more questions and more clarifications, and we’ll keep working through them. If something doesn’t match the book, use Report a Bug, tell us the rule and the page, and attach your files.
We also don’t know yet what the Core Rules will mean for infantry. As we covered in BattleTech Core Rules and the Old Ones, infantry is one of the areas Catalyst’s compatibility work is focused on, and we’ll follow wherever that lands. For now, this release is our version of the Marian Reforms. The Roman kind, not the Hegemony.
Next week, assuming ComStar lets go of it, Illiani’s post finally arrives with the economic changes coming to MekHQ in 0.51.01. Fair warning to anyone whose mercenary company is richer than the Federated Suns: your accountants want a word. And all those platoons you just dropped on a factory? Somebody has to pay them.
Keep your seals on and your flamers fueled!