Anti-ERA round
From the Multicrew Tank Combat wiki
An anti-ERA round is a round built to get past ERA. A normal round has to get through the panel's full protection and then the plate behind it. An anti-ERA round gets through the panel as if part of it, or all of it, was not there.
Most anti-ERA rounds are APFSDS with a special tip. A few top-attack missiles and shells have the same ability. Their warheads meet a panel's kinetic protection the way solid shot does, and not its HEAT protection.
Every one of these rounds has an ERA tip value on its shell page. APFSDS rounds that have one are also labelled "anti-ERA" in their type.
How it works
The ERA tip value is how much of a panel's protection against solid shot the round removes. A round with an ERA tip of 1 removes all of it from an old panel. A round with 0.15 removes 15%.
Modern panels fight back. The panel's tandem resistance, the same value that protects it from tandem warheads, reduces the effect. Against Kontakt-5 the reduction is tiny. Against Relikt, Duplet and Monolith it is large. That is what ERA tips above 1 are for.
The exact amount, for any round against any panel:
protection removed = ERA tip × (1 − tandem resistance2)
The result never goes above 100%.
Tandem resistance is the "Against tandem" figure on the ERA page, written as a fraction. For 
DM53 against a Relikt front panel that is 0.4 × (1 − 0.82), which comes to 14%.
An example with Kontakt-5:
Ordinary HEAT rounds get no anti-ERA effect. For HEAT, see Tandem warhead.
The tip only works on the first destructible part the round hits. If a rubber skirt or an external fuel tank sits in front of the real ERA, the skirt soaks up the effect and the ERA behind it works at full strength.
Rounds
| ERA tip | Rounds |
|---|---|
| 0.15 |  DM43A1, OFL 120 F1,  OFL 120 F2 |
| 0.4 | DM13, DM53, DM53A1, DM73, K279, SHARD®, Type 10, XH 45 |
| 1 | M829A3 |
| 1.66 | M829A4 |
| 2 |  DM702A1, KSTAM-II,  POLYNEGE, TOW-2B |
Protection removed
How much of its protection against solid shot each panel loses. The columns are the ERA tip of the round that hits it.
| Panel | 0.15 | 0.4 | 1 | 1.66 | 2 |
|---|---|---|---|---|---|
| Kontakt-1 | 15% | 40% | 100% | 100% | 100% |
| Rubber skirts and flaps | 15% | 40% | 100% | 100% | 100% |
| ERAWA-1 | 15% | 40% | 100% | 100% | 100% |
| Kontakt-5 | 15% | 39% | 98% | 100% | 100% |
| ERAWA-2 | 13% | 34% | 84% | 100% | 100% |
| FY-2 | 11% to 15% | 30% to 39% | 75% to 98% | 100% | 100% |
| Relikt, side panels | 11% | 30% | 75% | 100% | 100% |
| FY-4 | 11% | 30% | 75% | 100% | 100% |
| Kaktus | 10% | 26% | 64% | 100% | 100% |
| 4S22 and 4S24 | 8% | 23% | 56% | 94% | 100% |
| ARAT-1 | 8% | 23% | 56% | 94% | 100% |
| Nozh | 8% | 20% | 51% | 85% | 100% |
| ARAT-2 | 5% | 14% | 36% | 60% | 72% |
| ROMOR-A | 5% | 14% | 36% | 60% | 72% |
| Relikt, front panels | 5% | 14% | 36% | 60% | 72% |
| Duplet | 4% | 11% | 28% | 46% | 56% |
| FY-5 | 4% | 11% | 28% | 46% | 56% |
| Monolith | 4% | 11% | 28% | 46% | 56% |
| NERA | 3% to 8% | 8% to 23% | 19% to 56% | 32% to 94% | 38% to 100% |
| Composite screens | 3% | 8% | 19% | 32% | 38% |