Huh. Let's assume I didn't do this wrong:
A straight conversion, I guess, it's a variable amount based on your Magic Research Throw + Mods....
LL version: 9th level MU, INT 16+, rod, has a base chance of 10%; effect 11 takes that to 50%.
ACKS: 9th level Mage, INT 16+, rod, has a base chance of (8+, -13 > 21+, +2 INT > 19+) or 10%, same as above. Multiply that by 5 (10% > 50%) gets us a throw of 11+.
If we range that out to the entire spectrum of Magical Research throws, and, in addition, eliminate from consideration how you multiply a 0% chance of success by 5, and take into account the 15% failure rate for a throw of 1-3 for auto-success throws, we get:
| Throw with Mods |
-13 Penalty |
Regular Chance |
x5 Chance |
x5 Throw |
x5 Chance w/Failure |
| 8 |
21 |
0.00% |
0.00% |
21 |
0.00% |
| 7 |
20 |
5.00% |
25.00% |
16 |
25.00% |
| 6 |
19 |
10.00% |
50.00% |
11 |
50.00% |
| 5 |
18 |
15.00% |
75.00% |
6 |
75.00% |
| 4 |
17 |
20.00% |
100.00% |
1 |
85.00% |
| 3 |
16 |
25.00% |
125.00% |
1 |
85.00% |
| 2 |
15 |
30.00% |
150.00% |
1 |
85.00% |
| 1 |
14 |
35.00% |
160.00% |
1 |
85.00% |
| 0 |
13 |
40.00% |
160.00% |
1 |
85.00% |
| -1 |
12 |
45.00% |
160.00% |
1 |
85.00% |
| -2 |
11 |
50.00% |
160.00% |
1 |
85.00% |
| -3 |
10 |
55.00% |
160.00% |
1 |
85.00% |
| -4 |
9 |
60.00% |
160.00% |
1 |
85.00% |
| -5 |
8 |
65.00% |
160.00% |
1 |
85.00% |
| -6 |
7 |
70.00% |
160.00% |
1 |
85.00% |
So if you have a Magical Research Throw, in this particular situation, of 7+, by either being 10th level, or by some combination of other bonuses, your default chance adds 13 to your roll, for a roll of 20+ - or, 5%. By five that's 25%, which converts back to a throw of 16+.
After you get to a situational throw of 4+, you are only failing on the usual 1-3 of a Magic Research Throw with the multiplier.
In comparison, the LL Magic-User (INT 16+, Level 9+) can have a best chance of 20% if they know the Tongue of the Great Ancients (doubles), 50% with ward dropped, and up to 100% if they have both.
So...wider range of possibilities in ACKS with an overall cap of 15% failure rate.
If instead you take the "50% better chance" as halving the -13 penalty to -7:
| Throw with Mods |
-13 Penalty |
Regular Chance |
-7 Penalty |
-7 Chance w/Failure |
| 14 |
27 |
-45.00% |
21 |
0.00% |
| 13 |
26 |
-40.00% |
20 |
5.00% |
| 12 |
25 |
-35.00% |
19 |
10.00% |
| 11 |
24 |
-30.00% |
18 |
15.00% |
| 10 |
23 |
-25.00% |
17 |
20.00% |
| 9 |
22 |
-20.00% |
16 |
25.00% |
| 8 |
21 |
0.00% |
15 |
30.00% |
| 7 |
20 |
5.00% |
14 |
35.00% |
| 6 |
19 |
10.00% |
13 |
40.00% |
| 5 |
18 |
15.00% |
12 |
45.00% |
| 4 |
17 |
20.00% |
11 |
50.00% |
| 3 |
16 |
25.00% |
10 |
55.00% |
| 2 |
15 |
30.00% |
9 |
60.00% |
| 1 |
14 |
35.00% |
8 |
65.00% |
| 0 |
13 |
40.00% |
7 |
70.00% |
| -1 |
12 |
45.00% |
6 |
75.00% |
| -2 |
11 |
50.00% |
5 |
80.00% |
| -3 |
10 |
55.00% |
4 |
85.00% |
| -4 |
9 |
60.00% |
3 |
85.00% |
| -5 |
8 |
65.00% |
2 |
85.00% |
| -6 |
7 |
70.00% |
1 |
85.00% |
(-6 would shift everything up 5%)
...which increases the overall chance of failure after dropping the wards quite a bit.
I feel like the first option is probably more true to the intent, if the original intent was the LL version, but your mileage may vary.
The first table can be simplified as:
| Modified Magical |
|
|
| Research Throw |
Wards In Place |
Wards Dropped |
| 8+ or more |
- no chance- |
- no chance- |
| 7+ |
20+ |
16+ |
| 6+ |
19+ |
11+ |
| 5+ |
18+ |
6+ |
| 4+ |
17+ |
1+ |
| 3+ |
16+ |
1+ |
| 2+ |
15+ |
1+ |
| 1+ |
14+ |
1+ |
| 0+ |
13+ |
1+ |
| -1+ |
12+ |
1+ |
| -2+ |
11+ |
1+ |
| -3+ |
10+ |
1+ |
| -4+ |
9+ |
1+ |
| -5+ |
8+ |
1+ |
| -6+ |
7+ |
1+ |