Heat Scale Effects

Overheating in BTA has been completely overhauled and no longer deals structural damage. Instead, you can be forced to shutdown, experience ammo explosions, pilot injuries, or critical hits, and experience significant movement and attacking penalties. These changes are tied to the Classic BattleTech (CBT) extended heat scale, which normally ranges from 0 to 50 heat. The HBS game expanded heat values on a 3:1 basis, so this implementation uses a 0 to 150 scale for heat. Multiple effects can occur at the same heat level, which can result in the unit shutting down, having an ammo explosion, and injuring the pilot all at once!

The chance of a heat scale effect occurring is modified by the pilot's Guts skill, the higher your Guts the more chance you have to avoid the effects of overheating. When a roll is made for a heat event the Guts skill is multiplied by a set value (0.05) and the total is added to the roll value which is then compared to the event chance.

Example: a 'Mech with 66 heat has a 60% shutdown chance (threshold of 0.60). The pilot has a Guts of 4 meaning their Guts modifiers is 0.2 (4 x 0.05 = 0.2). The random roll value is 0.23 therefore the total calculation is 0.23 + (4 x 0.05) = 0.43 which is lower than the 0.60 threshold therefore the 'Mech shuts down.

Version 17.1 added an external heat limit.

External heat limit is the maximum amount of heat that can be applied by external sources, this limit is 85 above their neutral value, anything above this value from player actions is lost. A unit can still go above this limit through own actions.

External heat is also only applied if the target heat suppression for the current turn is 0 or below, if the target heat suppression, as in, the heat dissipation for the previous turn, has a delta of negative heat, this dissipation will be consumed before external heat is applied to the target

The chances below are displayed in a tooltip shown when hovering over the heat bar in the bottom left corner of the UI, just above the 'Mech paper doll. These values are dynamically updated when you target an enemy, so you can predict what will occur at the end of your turn.

• Shutdown Chance is the threshold a percentile check (d100) must equal or exceed, or the Mech will be forced into a Shutdown.
• System Failure Chance is the threshold a percentile check (d100) must equal or exceed, or one randomly selected internal component will be destroyed.
• Ammo Explosion Chance is the threshold a percentile check (d100) must equal or exceed, or the most damaging ammo box remaining will explode and inflict internal damage.
• Pilot Injury Chance is the threshold a percentile check (d100) must equal or exceed, or the Pilot will suffer one point of damage.
• Attack Modifier is a penalty to the unit's chance to hit.
• Movement Modifier is a penalty to the unit's base Walking Speed, which also reduces its running speed.

Heat Level	Shutdown	System Failure	Ammo Explosion	Pilot Injury	Attack Modifier	Movement Modifier
15	-	-	-	-	-	-
24	-	-	-	-	-1	-
30	-	-	-	-	-1	-28m
39	-	-	-	-	-2	-28m
42	10%	-	-	-	-2	-28m
51	10%	-	-	-	-3	-28m
54	30%	-	-	-	-3	-28m
57	30%	10%	-	-	-3	-28m
60	30%	10%	40%	-	-3	-56m
66	60%	10%	40%	-	-3	-56m
69	60%	30%	40%	-	-3	-56m
72	60%	30%	40%	-	-4	-56m
75	60%	30%	40%	-	-4	-56m
78	80%	30%	40%	-	-4	-56m
84	80%	50%	40%	30%	-4	-56m
90	90%	50%	60%	30%	-4	-56m
93	90%	50%	60%	30%	-4	-84m
99	90%	50%	60%	30%	-5	-84m
102	100%	50%	60%	30%	-5	-84m
105	100%	80%	60%	30%	-5	-84m
108	100%	80%	60%	30%	-5	-84m
111	100%	80%	60%	30%	-5	-84m
114	110%	80%	60%	30%	-5	-84m
117	110%	80%	60%	60%	-5	-84m
120	110%	95%	100%	60%	-5	-84m
123	110%	95%	100%	60%	-6	-84m
126	120%	95%	100%	60%	-6	-84m
129	120%	95%	100%	60%	-6	-112m
132	120%	95%	100%	60%	-6	-112m
135	120%	Auto	100%	60%	-6	-112m
138	130%	Auto	100%	60%	-6	-112m
141	130%	Auto	100%	80%	-6	-112m
144	130%	Auto	100%	80%	-7	-112m
147	130%	Auto	100%	80%	-7	-112m
150	Auto	Auto	100%	80%	-7	-112m